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 A029726 #36 Jul 08 2025 19:18:49 %S A029726 1,1,1,2,5,9,22,40,137,223,430,788,2537,4558,12136,24871,95526,182234 %N A029726 Number of conjugacy classes of subgroups of the alternating group A_n. %C A029726 Number of even permutation groups; also number of molecular species based on even permutation groups. - _Christian G. Bower_, Feb 23 2006 %H A029726 L. Naughton and G. Pfeiffer, <a href="http://arxiv.org/abs/1211.1911">Integer Sequences Realized by the Subgroup Pattern of the Symmetric Group</a>, arXiv preprint arXiv:1211.1911, 2012 and <a href="https://cs.uwaterloo.ca/journals/JIS/VOL16/Naughton/naughton2.html">J. Int. Seq. 16 (2013) #13.5.8</a> %H A029726 Götz Pfeiffer, <a href="https://web.archive.org/web/20080526152820/http://schmidt.nuigalway.ie/subgroups/">Numbers of subgroups of various families of groups</a> %H A029726 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a> %o A029726 (GAP) %o A029726 # GAP 4.2 %o A029726 Length(ConjugacyClassesSubgroups(AlternatingGroup(n))); %o A029726 (Magma) n := 5; #SubgroupLattice(Alt(n)); %Y A029726 Cf. A000001, A000638. Unlabeled version of A029725. Euler transform of A116653. %K A029726 hard,nonn,more %O A029726 0,4 %A A029726 _N. J. A. Sloane_ %E A029726 More terms from _Reiner Martin_, Dec 30 2001 %E A029726 a(10)-a(13) added by _Christian G. Bower_, Feb 23 2006 based on Goetz Pfeiffer's web page. %E A029726 a(14)-a(17) from _Vaclav Kotesovec_, Jul 21 2022