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 A066060 #36 Feb 16 2025 08:32:45 %S A066060 1,1,1,2,1,1,1,5,2,1,1,2,1,1,1,14,1,2,1,2,1,1,1,5,2,1,5,2,1,1,1,51,1, %T A066060 1,1,4,1,1,1,5,1,1,1,2,2,1,1,14,2,2,1,2,1,5,1,5,1,1,1,2,1,1,2,267,1,1, %U A066060 1,2,1,1,1,10,1,1,2,2,1,1,1,14,15,1,1,2,1,1,1,5,1,2,1,2,1,1,1,51,1,2,2,4,1 %N A066060 Number of nilpotent groups of order n. %C A066060 Multiplicative with a(p^m) equal to the number of groups of order p^m. %H A066060 T. D. Noe and Amiram Eldar, <a href="/A066060/b066060.txt">Table of n, a(n) for n = 1..2047</a> (terms 1..2015 from T. D. Noe) %H A066060 John Renze, <a href="https://mathworld.wolfram.com/NilpotentGroup.html">Nilpotent Group</a>. %t A066060 terms = 101; fgc = FiniteGroupCount[Range[terms]]; a[1] = 1; a[n_ /; PrimePowerQ[n] && 1 < n <= terms] := a[n] = fgc[[n]]; a[n_ /; 1 < n <= terms] := a[n] = Times @@ (a[#[[1]]^#[[2]]]& /@ FactorInteger[n]); Array[a, terms] (* _Jean-François Alcover_, Oct 03 2017 *) %Y A066060 Cf. A000001, A056867, A069739. %K A066060 nonn,nice,mult,easy %O A066060 1,4 %A A066060 _Reiner Martin_, Dec 29 2001