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 A029725 #23 Jul 08 2025 19:18:42 %S A029725 1,1,1,2,10,59,501,3786,48337,508402,6469142,81711572,2019160542, %T A029725 31945830446,749115591093,15230426073946,617313283787616, %U A029725 13472047923890487 %N A029725 Number of distinct subgroups of alternating group A_n, counting conjugates as distinct. %H A029725 L. Naughton, G. Pfeiffer, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL16/Naughton/naughton2.html">Integer Sequences Realized by the Subgroup Pattern of the Symmetric Group</a>, J. Int. Seq. 16 (2013) #13.5.8 %H A029725 Götz Pfeiffer, <a href="http://schmidt.nuigalway.ie/subgroups">Numbers of subgroups of various families of groups</a> %H A029725 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a> %F A029725 Exponential transform of A116652. - _Christian G. Bower_, Feb 23 2006 %o A029725 (Magma) n := 5; &+[ Length(s):s in SubgroupLattice(Alt(n)) ]; %Y A029725 Cf. A005432. Labeled version of A029726. %K A029725 nonn %O A029725 0,4 %A A029725 _N. J. A. Sloane_ %E A029725 a(9)-a(13) added by _Christian G. Bower_, Feb 23 2006 based on Goetz Pfeiffer's web page. %E A029725 a(14)-a(17) from _Vaclav Kotesovec_, Jul 21 2022