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 A074880 #7 Jul 02 2018 22:37:58 %S A074880 1,1,1,3,6,120,120,1260,6720,128520,362880,20041560,39916800, %T A074880 1132971840,11721790080,163459296000,1307674368000,87307501881600, %U A074880 355687428096000,19137704006453760,205947392645030400,5118231678995635200,51090942171709440000,4769913628444053196800 %N A074880 Number of labeled cyclic subgroups of S_n having order n. %H A074880 Andrew Howroyd, <a href="/A074880/b074880.txt">Table of n, a(n) for n = 1..200</a> %F A074880 a(n) = A074351(n)/A000010(n). %o A074880 (PARI) a(n)={n!*polcoeff(sumdiv(n, i, moebius(n/i)*exp(sumdiv(i, j, x^j/j) + O(x*x^n))), n)/eulerphi(n)} \\ _Andrew Howroyd_, Jul 02 2018 %Y A074880 Cf. A051625, A074260. %K A074880 nonn %O A074880 1,4 %A A074880 _Vladeta Jovovic_, Sep 30 2002 %E A074880 Terms a(22) and beyond from _Andrew Howroyd_, Jul 02 2018