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 A218963 #22 Jul 17 2018 12:17:08 %S A218963 1,1,1,1,7,31,121,806,5706,40902,345444,3627834,44916840,473882124, %T A218963 5607925896,73429902300,1169960275680,18289685306640,315392669158416, %U A218963 5046227338720884,98328156602878800,1862418125263338720,36536960773307025360,777453614193997039320 %N A218963 Total number of maximal cyclic subgroups of the alternating group, counting conjugates as distinct. %H A218963 Andrew Howroyd, <a href="/A218963/b218963.txt">Table of n, a(n) for n = 0..50</a> %H A218963 Liam Naughton and Goetz Pfeiffer, <a href="http://arxiv.org/abs/1211.1911">Integer sequences realized by the subgroup pattern of the symmetric group</a>, arXiv:1211.1911 [math.GR], 2012-2013. %H A218963 Liam Naughton, <a href="http://www.maths.nuigalway.ie/~liam/CountingSubgroups.g">CountingSubgroups.g</a> %H A218963 Liam Naughton and Goetz Pfeiffer, <a href="http://schmidt.nuigalway.ie/tomlib/">Tomlib, The GAP table of marks library</a> %o A218963 (PARI) \\ See A218958 for PARI script file. %o A218963 a(n)=MaximalCyclicSubgroupCount(n, v->sum(i=1, #v, v[i]-1)%2==0); \\ _Andrew Howroyd_, Jul 17 2018 %Y A218963 Cf. A051636, A218932, A218949, A218958. %K A218963 nonn %O A218963 0,5 %A A218963 _Liam Naughton_, Nov 23 2012 %E A218963 a(3)-a(13) corrected by _Liam Naughton_, Jul 17 2018 %E A218963 Terms a(14) and beyond from _Andrew Howroyd_, Jul 17 2018