%I #28 Feb 17 2022 16:05:02

%S 0,1,2,5,19,78,421,2637,20486,246458,11833361

%N Number of isomorphism classes of commutative monoids (commutative semigroups with identity) of order n.

%H Remigiusz Durka and Kamil Grela, <a href="https://arxiv.org/abs/1911.12814">On the number of possible resonant algebras</a>, arXiv:1911.12814 [hep-th], 2019.

%H Eric Postpischil, <a href="https://groups.google.com/forum/?hl=en#!msg/sci.math/nU-hg-FFSFo/iIB3Lul1sAEJ">Posting to sci.math newsgroup, May 21 1990</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CommutativeMonoid.html">Commutative Monoid</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/AdditiveCellularAutomaton.html">Additive Cellular Automaton</a>

%H Stephen Wolfram, <a href="http://wolframscience.com/">A New Kind of Science</a>, Wolfram Media, 2002; p. 952.

%H <a href="/index/Mo#monoids">Index entries for sequences related to monoids</a>

%Y Row sums of A058142.

%Y Cf. A001426, A058129, A058155 (labeled).

%K nonn,more

%O 0,3

%A _Christian G. Bower_, Nov 13 2000

%E a(0) prepended by _Jianing Song_, Oct 26 2019

%E a(8) and a(9) from _Alex Meiburg_, Oct 20 2021

%E a(10) from _Andrew Howroyd_, Feb 15 2022