cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A058132 Number of self-converse monoids (semigroups with identity) of order n.

Original entry on oeis.org

0, 1, 2, 5, 19, 84, 509, 3901, 48957
Offset: 0

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Author

Christian G. Bower, Nov 13 2000

Keywords

Crossrefs

Formula

a(n) = A058133(n)*2 - A058129(n).

Extensions

a(8) from Max Alekseyev, Jul 13 2009
a(0) prepended by Jianing Song, Oct 26 2019