On-Line Encyclopedia of Integer Sequences

The On-Line Encyclopedia of Integer Sequences (OEIS), also known as Sloane's, is a large searchable database. It is on the Web, and it contains number sequences, like the Fibonacci numbers or the powers of two.

It contains over 270,000 sequences. This makes it the largest database of its kind. Each entry contains the leading terms of the sequence, keywords, mathematical motivations, literature links. It also includes the option to generate a graph or play a musical representation of the sequence. The database can be searched by keyword and by subsequence. For instance, it is possible to search for all sequences with both 15 and 118.

On-Line Encyclopedia Of Integer Sequences Media

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  The official logo of the On-Line Encyclopedia of Integer Sequences

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  Sloane's "Integer Sequences" web page on the "AT&T research" web site as of 1999.

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  Plot of Sloane's Gap : number of occurrences (Y log scale) of each integer (X scale) in the OEIS database