From the text: This article gives a brief introduction to the On-Line Encyclopedia of Integer Sequences (or OEIS). The OEIS is a database of nearly 90,000 sequences of integers, arranged lexicographically. The entry for a sequence lists the initial terms (50 to 100, if available), a description, formulae, programs to generate the sequence, references, links to relevant web pages, and other information.
Since 1996 an electronic version has been accessible via the Internet at
http://www.research.att.com/~njas/sequences/. If a list of numbers is entered there, the reply will display the entries for all matching sequences.