Special Colloquium Talk


Title: Recent Acquisitions in the On-Line Encyclopedia of Integer Sequences

Speaker: Neil J.A. Sloane, AT&T Shannon Labs and DIMACS

Date: Tuesday, May 4, 2004

Reception before the talk: 4 PM, DIMACS Lounge, Room 401

Lecture: 4:30pm

Location: DIMACS Center, CoRE Bldg, Room 431, Busch Campus, Piscataway, NJ

Sponsored by:

For further information please contact Christine Houck (houck@dimacs.rutgers.edu)


Abstract:

The On-Line Encyclopedia of Integer Sequences (OEIS) is a database of number sequences that enables users to check if a sequence that has arisen in their work has been studied by others. A typical entry gives the first 50 or so terms of the sequence, formulas, references, links, computer programs for producing the sequence, etc.

The OEIS now contains 90,000 sequences and gets over 20,000 hits per day. Over ten thousand new sequences were added in the past year. I will discuss some highlights, including ``dismal'' primes, the amazing Recaman and Gijswijt sequences, and sequences arising from non-classical error correcting codes suggested by the Internet. I will also give three examples of unexpected connections between apparently unrelated sequences, from graph theory, wireless communications, and data compression.

Finally, a very recent sequence has led to a lovely and as-yet unsolved question about numerators of Bernoulli numbers.