Do you recognize the sequence 1, 2, 5, 14, 42, 132, 429, ... ? Do
you know what the next term should be? Check out the index of integer
sequences maintained by
Neil Sloane.
(Yes, I know, the number of sequences that start out this way is
infinite, but the sequence of Catalan numbers is the
only one that I know of that is interesting or useful.)
Do you recognize the real number 1.6180339887 ... ? Look it up in
the Inverse Symbolic Calculator, a project of the
Centre for Experimental & Constructive
Mathematics, and you will find that it matches
the number (1 + sqrt(5))/2, the "golden ratio".
Do you know your Erdös number? Do you know what an Erdös number
is? Find out at the Erdös Number Project Home Page, maintained by
Jerry Grossman
and Patrick Ion. (My Erdös number is 2.)
Who was Donald Knuth's Ph.D. advisor? Did Alan Turing have any
Ph.D. students? Find out by consulting the Theoretical Computer Science
Genealogy project of SIGACT.
My academic ancestors include Frank Harary, Alfred Foster, Alonzo Church,
Oswald Veblen, E. H. Moore, and H. A. Newton. My great uncles
include Stephen Kleene, Alan Turing, John Kemeny, Hartley Rogers,
Michael Rabin, Dana Scott, Raymond Smullyan, and others, all students of
Church. Check out your own academic family tree.
Mathematicians are playing the genealogy game now, too. This
project is attempting to build a data base of all people who have
received a doctorate in mathematics. When I last checked, there were 8
mathematicians named Newton in the database, but none with first name
Issac.
Has Fermat's Last Theorem been proved? What is the largest known
prime number? How can one compute the digits of pi? Is 0.999 ...
really equal to 1? Who is Nicholas Bourbaki? What is the Monty Hall
Problem? Find answers to these and scores of other questions about
mathematics at the Web Site of the
sci.math FAQ team, lead by
Alex
López-Ortiz. He also maintains a Frequently
Asked Questions in Theoretical Computer Science page, but it's a
little rough yet.
This page is maintained by Paul
K. Stockmeyer. Select my name to see my home page.
The URL for this page is
http://www.cs.wm.edu/~pkstoc/fun_stuff.html
Last updated 25 July 2005