### 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:

- DIMACS
- Department of Mathematics - Rutgers University
- Department of Computer Science - Rutgers University
- Department of Electrical and Computer Engineering - Rutgers University
- Department of Statistics - Rutgers University
- Center for Advanced Information Processing (CAIP)
- Rutgers Center for Operations Research (RUTCOR)

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.