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%I #34 Dec 23 2023 14:29:14
%S 1,1,1,2,5,9,22,40,137,223,430,788,2537,4558,12136,24871,95526,182234
%N Number of conjugacy classes of subgroups of the alternating group A_n.
%C Number of even permutation groups; also number of molecular species based on even permutation groups. - _Christian G. Bower_, Feb 23 2006
%H 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 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 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%o (GAP)
%o # GAP 4.2
%o Length(ConjugacyClassesSubgroups(AlternatingGroup(n)));
%o (Magma) n := 5; #SubgroupLattice(Alt(n));
%Y Cf. A000001, A000638. Unlabeled version of A029725. Euler transform of A116653.
%K hard,nonn,more
%O 0,4
%A _N. J. A. Sloane_.
%E More terms from _Reiner Martin_, Dec 30 2001
%E a(10)-a(13) added by _Christian G. Bower_, Feb 23 2006 based on Goetz Pfeiffer's web page.
%E a(14)-a(17) from _Vaclav Kotesovec_, Jul 21 2022