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.
%I A058131 #29 Feb 16 2025 08:32:43 %S A058131 0,1,2,5,19,78,421,2637,20486,246458,11833361 %N A058131 Number of isomorphism classes of commutative monoids (commutative semigroups with identity) of order n. %H A058131 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 A058131 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 A058131 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CommutativeMonoid.html">Commutative Monoid</a> %H A058131 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AdditiveCellularAutomaton.html">Additive Cellular Automaton</a> %H A058131 Stephen Wolfram, <a href="http://wolframscience.com/">A New Kind of Science</a>, Wolfram Media, 2002; p. 952. %H A058131 <a href="/index/Mo#monoids">Index entries for sequences related to monoids</a> %Y A058131 Row sums of A058142. %Y A058131 Cf. A001426, A058129, A058155 (labeled). %K A058131 nonn,more %O A058131 0,3 %A A058131 _Christian G. Bower_, Nov 13 2000 %E A058131 a(0) prepended by _Jianing Song_, Oct 26 2019 %E A058131 a(8) and a(9) from _Alex Meiburg_, Oct 20 2021 %E A058131 a(10) from _Andrew Howroyd_, Feb 15 2022