On-Line Encyclopedia of Integer Sequences

On-Line Encyclopedia of Integer Sequences

Founded	1964; 59 years ago (1964)
Predecessor(s)	Handbook of Integer Sequences, Encyclopedia of Integer Sequences
Created by	Neil Sloane
Chairman	Neil Sloane
President	Russ Cox
URL	oeis.org
Commercial	No[1]
Registration	Optional[2]
Launched	1996; 27 years ago (1996)
Content license	Creative Commons CC BY-SA 4.0[3]

The On-Line Encyclopedia of Integer Sequences (OEIS) is an online database of integer sequences. It was created and maintained by Neil Sloane while researching at AT&T Labs. He transferred the intellectual property and hosting of the OEIS to the OEIS Foundation in 2009.^[4] Sloane is the chairman of the OEIS Foundation.

OEIS records information on integer sequences of interest to both professional and amateur mathematicians, and is widely cited. As of November 2023^[ref], it contains over 367,000 sequences,^[5] making it the largest database of its kind.^{[citation needed]}

Each entry contains the leading terms of the sequence, keywords, mathematical motivations, literature links, and more, including the option to generate a graph or play a musical representation of the sequence. The database is searchable by keyword, by subsequence, or by any of 16 fields.