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The Connoisseur of Number Sequences

Posted by samzenpus on from the math-man dept.

An anonymous reader writes: 75-year-old Neil Sloane is considered by many to be one of the most influential mathematicians of our time, not because of the theorems he's proved, but because of his creation: The Online Encyclopedia of Integer Sequences (OEIS). Quanta Magazine reports: "This giant repository, which celebrated its 50th anniversary last year, contains more than a quarter of a million different sequences of numbers that arise in different mathematical contexts, such as the prime numbers (2, 3, 5, 7, 11 ) or the Fibonacci sequence (0, 1, 1, 2, 3, 5, 8, 13 ). What's the greatest number of cake slices that can be made with n cuts? Look up sequence A000125 in the OEIS. How many chess positions can be created in n moves? That's sequence A048987. The number of ways to arrange n circles in a plane, with only two crossing at any given point, is A250001. That sequence just joined the collection a few months ago. So far, only its first four terms are known; if you can figure out the fifth, Sloane will want to hear from you."

11 of 63 comments (clear)

  1. A250001 by Anonymous Coward · · Score: 2, Funny

    COMMENTS a(5) reduced by 1 because of a takedown order by the IOC for their trademarked 5-ring configuration.

  2. 50th anniversary "on-line"? by tverbeek · · Score: 5, Informative

    If you're wondering how an "on-line" collection celebrated its 50th anniversary recently: the collection was begun in 1964; it was made available via the Internet starting in 1996.

    --
    http://alternatives.rzero.com/
  3. 75-year-old Neil Sloane is considered by many by Anonymous Coward · · Score: 2, Insightful

    Who are these "many"? Horrible journalism.

    1. Re:75-year-old Neil Sloane is considered by many by Rockoon · · Score: 2

      Who are these "many"? Horrible journalism.

      Probably talking about people like me, who have saved many hours of effort multiple times per year since discovering it over a decade ago.

      --
      "His name was James Damore."
    2. Re:75-year-old Neil Sloane is considered by many by JoshuaZ · · Score: 4, Informative

      Mathematicians. I don't how many times I've seen a sequence of integers and then gone to Sloane's encyclopedia to see if the sequence is known. This is helpful in both not duplicating others work (e.g. finding out that something one has found is already known) or b) identifying that a given sequence is a known sequence and then using that as a guideline on what to prove. That last bit happens surprisingly often when one has combinatorial structure to something: pop the sequence of numbers you've got into his database and it will tell you something like the first 6 terms matching some nice combinatorial thing and then you can with that guidance go and prove that in general that's what the sequence really is.

    3. Re:75-year-old Neil Sloane is considered by many by plcurechax · · Score: 3, Informative

      Who are these "many"? Horrible journalism.

      Unsurprisingly, mathematicians. Many mathematicians use the OEIS frequently, heck experts and professionals from other disciplines like Computer Science, Economics, or Physics routinely use OEIS to identify numeric sequences or patterns.

      I'd hazard to say anyone who calls themselves a mathematician has used OEIS (or the book version) at least once. In fact I'd be surprised if you could find anyone with a graduate degree in mathematics who doesn't know who Neil Sloane or OEIS are.

      Yes, it is that important.

  4. A Cinco Product. by xenotransplant · · Score: 2

    Encyclopedia of Numbers

  5. Re:One of the worst words in the english language by Anonymous Coward · · Score: 2, Insightful

    Actually "connoisseur" was the correct French spelling when English borrowed it, and later the French spelling was changed. Racemaniac should study his native language a little bit more before pointing fingers.

  6. Re:One of the worst words in the english language by khallow · · Score: 2

    You do realize that the French language has changed the spelling of many of its words over the centuries? Glancing through the online dictionaries, it appears the word "connoisseur" entered the English language around the beginning of the 18th century, 300 years ago. And there's some French words that came over with William the Conqueror almost a millennium ago.

  7. Elevator sequence by glitch! · · Score: 4, Funny

    I like the sequence: 1,2,1,1,1,1 ...

    The X axis is the number of people in an elevator.
    The Y axis is how many people know which one farted.

    --
    A dingo ate my sig...
  8. Re: Handbooks by plcurechax · · Score: 2

    Any of you old timers remember the Chemical Rubber Handbook? It's a site now also:
    http://www.hbcpnetbase.com/

    I admit I've always heard it called the CRC Handbook(s). The "original" being their Chemistry and Physics one (the one at the link), though CRC Press does tons of technical, scientific printing in the US, they also have handbooks on topics in computer science, computer security and many others.

    And my copy is I think 80-something-th edition.