A058132 - OEIS

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A058132

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

4

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

Table of n, a(n) for n=0..8.

Index entries for sequences related to monoids

FORMULA

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

CROSSREFS

Cf. A058129, A058133.

Sequence in context: A179566 A107377 A286886 * A286071 A002851 A354621

Adjacent sequences: A058129 A058130 A058131 * A058133 A058134 A058135

KEYWORD

nonn,more

AUTHOR

Christian G. Bower, Nov 13 2000

EXTENSIONS

a(8) from Max Alekseyev, Jul 13 2009

a(0) prepended by Jianing Song, Oct 26 2019

STATUS

approved