Happy Anniversary

Heidi and I have been married 17 wonderful years today. In honor of this here are some facts about 17 (thanks to wikipedia)

In mathematics

Seventeen is the 7th prime number. The next prime is nineteen, with which it forms a twin prime. 17 is the sum of the first four primes. 17 is the sixth Mersenne prime exponent, yielding 131071. 17 is an Eisenstein prime with no imaginary part and real part of the form 3n − 1.

17 is the third Fermat prime, as it is of the form 2^{2^2} + 1, and it is also a Proth prime. Since 17 is a Fermat prime, heptadecagons can be drawn with compass and ruler. This was proven by Carl Friedrich Gauss.[1] Another consequence of 17 being a Fermat prime is that it is not a Higgs prime for squares or cubes.

17 is the only positive Genocchi number that is prime, the only negative one being -3. It is also the third Stern prime.

As 17 is the least prime factor of the first twelve terms of the Euclid-Mullin sequence, it is the thirteenth term.

Seventeen is the aliquot sum of two numbers, the odd discrete biprimes 39 and 55 is the base of the 17-aliquot tree.

There are exactly seventeen two-dimensional space (plane symmetry) groups. These are sometimes called wallpaper groups, as they represent the seventeen possible symmetry types that can be used for wallpaper.

Like 41, the number 17 is a prime that yields primes in the polynomial n2 + n + p, for all positive n < p - 1.

Consider a sequence of real numbers between 0 and 1 such that the first two lie in different halves of this interval, the first three in different thirds, and so forth. The maximum possible length of such a sequence is 17 (Berlekamp & Graham, 1970, example 63).

Either 16 or 18 unit squares can be formed into rectangles with perimeter equal to the area; and there are no other natural numbers with this property. The Platonists regarded this as a sign of their peculiar propriety; and Plutarch notes it when writing that the Pythagoreans "utterly abominate" 17, which "bars them off from each other and disjoins them".[2]

17 is the tenth Perrin number, preceded in the sequence by 7, 10, 12.

In base 9, the smallest prime with a composite sum of digits is 17.

17 is known as the Feller number, after the famous mathematician William Feller who taught at Princeton University for many years. Feller would say, when discussing an unsolved mathematical problem, that if it could be proved for the case n = 17 then it could be proved for all positive integers n. He would also say in lectures, "Let's try this for an arbitrary value of n, say n=17."

Similar to Feller, Prof. Vadim Khayms of Stanford University is also known to use 17 as an arbitrary value during lectures. His Computational Mathematics for Engineers course includes 17 lectures.

17 is the least random number[3], according to the Hackers' Jargon File. There is a proven theorem that 17 is the value most likely to be picked as a "random" number when such is needed in journalism which is derived from the Feller number.[4]

It is a repunit prime in hexadecimal (11).

It is believed that the minimum possible number of givens for a sudoku puzzle with a unique solution is 17, but this has yet to be proven.

There are 17 orthogonal curvilinear coordinate systems (to within a conformal symmetry) in which the 3-variable Laplace equation can be solved using the separation of variables technique.

17 is the first number that can be written as the sum of a positive cube and a positive square in two different ways; that is, the smallest n such that x3 + y2 = n has two different solutions for x and y positive integers. The next such number is 65.

In science

* The atomic number of chlorine.
* The Brodmann area defining the primary visual processing area of mammallian brains.
* Group 17 of the periodic table are the Halogens.

Age 17

* In the United States, the age at which one may purchase M-rated video games according to ESRB ratings.
* Also in some of the states in the United States, seventeen is the age of consent.
* In most states of the United States and the UK, the age at which you may donate blood.
* In many countries and regions, the age at which one may obtain a driver's license.
* In the United States, the age at which one may rent or purchase R Rated movies by himself/herself according to MPAA film rating system.

In culture

Music

* 17 is a number of obsession used by horrorcore rappers, Insane Clown Posse. The song "17 Dead" off their first EP "Belverly Kills 50187" uses the number frequently. Many of their songs reference the number 17 and most of their LP's contain 17 tracks.
* "(She's) Sexy + 17" was a 1983 Top 10 hit for Stray Cats from the album Rant N' Rave with the Stray Cats.
* "At Seventeen" was a 1975 hit by Janis Ian.
* "17", a song recorded by Rick James, in the album Reflections.
* The ratio 18/17 was a popular approximation for the equal tempered semitone during the Renaissance.
* "Seventeen" was the original name of The Beatles song "I Saw Her Standing There"..
* "17", a B-Side by Shiina Ringo on the "Tsumi to Batsu" single.
* The title of the song "17" by the Smashing Pumpkins. It is 17 seconds long, with no vocals, but comes with a poem which read at a standard speed will finish at the end of the song. This song is also a musical allusion to another Smashing Pumpkins work called "Blissed and Gone" which references 17 in the lines "Sweet 17, sour 29" and "I had no cause, just 17 days of rain".
* "17", a song recorded by Winger.
* "17", a song by yourcodenameis:milo.
* "Seventeen", a song by Ladytron.
* "Seventeen" by Jimmy Eat World
* "Seventeen Ain't So Sweet" a song by The Red Jumpsuit Apparatus.
* "17" a song by Kings of Leon.
* "Edge of Seventeen", a song from the 1981 album Bella Donna by Stevie Nicks.
* "17" by Milburn
* 17 Hippies, German band
* "Seventeen Forever" a song by Metro Station (band)
* Seventeen Days, 3rd studio album from American rock band 3 Doors Down.
* Dancing Queen by Abba features the line 'You are the Dancing Queen, young and sweet, only 17'.
* "All Summer Long" by Kid Rock features the line 'She was 17 but she was far from in between'.
* "Strawberry Wine" by Deana Carter features the line 'Strawberry Wine, 17, the hot July moon saw everything'.
* "God Love Her" by Toby Keith features the line 'The way a girl gets when she turns 17, kinda crazy'.
* "Sheer Heart Attack" by Queen features the line 'Well you're just 17 and all you want to do is disappear'.
* "Seventeen" is the sixth song on the album Give Me a Wall by ¡Forward, Russia!
* "Hello, Seventeen" by 12012
* "17 Again" is a song by Eurythmics as featured on their 1999 album Peace
* "Seventeen Seconds" is the second studio album by The Cure, released in April 1980 by Fiction Records.

Film

* Number Seventeen (1932), directed by Alfred Hitchcock
* Stalag 17 (1953), directed by Billy Wilder
* In 2004, Volatile Films released a feature length film titled The Significance of Seventeen starring Cindy Taylor; one theme addressed by the film is the high incidence of the number 17 and its function as 'the most random number' as described by MIT.
* In the film Three Days of the Condor, the title character played by Robert Redford works in section 17 of the CIA.
* In the Halloween film series the number 17 frequently reappears. Primarily with the age of people Michael Myers kills. Judith Myers is killed at 17 in the start of the first film, and Laurie Strode (the main character of the first films) is 17 when Michael Myers starts hunting her.
* 17 Again (2009), directed by Burr Steers

Print

* The title of Seventeen, a magazine.
* The number 17 is a recurring theme in the works of novelist Steven Brust. All of his chaptered novels have either 17 chapters or two books of 17 chapters each. Multiples of 17 frequently appear in his novels set in the fantasy world of Dragaera, where the number is considered holy.
* In The Illuminatus! Trilogy, the symbol for Discordianism includes a pyramid with 17 steps because 17 has "virtually no interesting geometric, arithmetic, or mystical qualities". However, for the Illuminati, 17 is tied with the "23/17 phenomenon".
* In the Harry Potter universe, 17 is the coming of age for wizards. It is equivalent to the usual coming of age at 18.

Religion

* According to Leon Kass, 17 has some significant meaning (as yet not known exactly) in the book of Genesis.[5]
* In the Yasna of Zoroastrianism seventeen chapters were written by Zoroaster himself, these are the Gathas.
* The number of the raka'ahs that Muslims perform during Salah on a daily basis.
* The number of surat al-Isra in the Qur'an.

In sports

* The most famous Ford number in the V8 Supercar championship, Driven by Dick Johnson to bring 5 Australian Touring Car Championships to his name. Now driven by son Steven Johnson.
* NASCAR driver Matt Kenseth's car number.
* The retired jersey number of former baseball pitcher Dizzy Dean.
* The number of former Chicago Cubs first baseman Mark Grace.
* The number of retired hockey player Wendel Clark
* The number of ice hockey player Chris Chaney
* The number of ice hockey player Rod Brind'Amour
* The number of ice hockey player Ilya Kovalchuk
* The number of ice hockey player Petr Sykora
* The number of ice hockey player Jeff Carter
* The number of ice hockey player Milan Lucic
* The former number of Right Winger Jean-Pierre Dumont when he played for the Buffalo Sabres
* The number of Hall of Fame basketball player John Havlicek
* The number of New York Giants' Wide Receiver Plaxico Burress
* The number of Cleveland Browns Wide Receiver Braylon Edwards
* The number of Toronto Blue Jays third baseman Kelly Gruber, and current first baseman Lyle Overbay
* The number that footballer Marc-Vivien Foé wore for the French clubs Lens and Lyon, retired by both clubs after his death from heart failure during a semifinal match in the 2003 FIFA Confederations Cup. Foé also wore the 17 shirt for the Cameroon national team at the time of his death.
* Real Madrid striker Ruud van Nistelrooy's shirt number
* The number that Cristiano Ronaldo wore on the Portuguese National Team, before switching to number 7 after the retirement of Luís Figo.
* The number of Carolina Panthers Quarterback Jake Delhomme.
* The number of Washington Redskins Quarterback Jason Campbell.
* The number of Colorado Rockies first baseman Todd Helton.
* The number of Arizona Diamondbacks pitcher Brandon Webb.
* The number of NBA Championships won by the Boston Celtics.
* The number of Tuncay Şanlı in the Turkish national team while scoring against Greece in the 1-4 match in Athens.
* The number of Ken Griffey Jr. while playing for Chicago White Sox.
* The number of Ateneo Blue Eagles and GMA Network tv - host Chris Tiu
* The number of former Collingwood Football Club Captain Scott Burns when he played from 1995 until 2008.

Seventeen is:

* Described at MIT as 'the most random number', according to hackers' lore. This is supposedly because in a study where respondents were asked to choose a random number from 1 to 20, 17 was the most common choice.
* The number of laws of the game in Association Football
* The number of guns in a 17-gun salute to U.S. Army, Air Force and Marine Corps Generals, and Navy and Coast Guard Admirals.
* The number of flames emanating from the grenade cap-badge of the Grenadier Guards.
* During the Second World War, the four-engined heavy bomber as flown by the USAAF and other Allies and known as "The Flying Fortress", was also known as the B-17.
* A mild swear word in Swedish. The origin is debated, and is commonly used as "sjutton också!" ("seventeen, too!"). It can roughly be translated to "Darn!". It is of course also used for the number 17.
* The maximum number of strokes of a Chinese radical.
* The number of syllables in a haiku (5+7+5).
* In the Nordic countries the seventeenth day of the year is considered the heart and/or the back of winter.
* The designation of United States Interstate 17, a freeway in Arizona.
* The designation of U.S. Route 17, a highway that runs from Virginia to Florida.
* Seventeen, also known as Lock Seventeen, an unincorporated place in Clay Township, Tuscarawas County, Ohio.
* Seventeen was the former name of a yacht prior to being commissioned in the US Navy as the USS Carnelian (PY-19).
* The number of special significance to Yellow Pig's Day and Hampshire College Summer Studies in Mathematics.
* In Italian culture, the number 17 is considered unlucky. When viewed as the Roman numeral, XVII, it is then changed anagramtically to VIXI, which in the Latin language it translates to "I have lived", the perfect tense implying "My life is over." (c.f. "Vixerunt", Cicero's famous announcement of an execution.) The Italian airline carrier, Alitalia, does not have a seat 17. Renault sold its "R17" model in Italy as "R177." See Cesana Pariol in the sport section about the name of curve 17.
* Android 17, a fictional character in the metaseries Dragon Ball.
* Some species of cicadas have a life cycle of 17 years (i.e. they are buried in the ground for 17 years between every mating season).
* The number to call Police in France.
* The number that symbolizes the soul.
* Force 17, a special operations unit of the Palestinian Fatah movement.
* The number of the French department Charente-Maritime