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 A242101 #20 Aug 23 2014 09:06:58 %S A242101 1,2,4,6,8,12,16,24,32,44,58,80,104,138,180,236,302,390,496,634,800, %T A242101 1010,1264,1586,1970,2448,3024,3734,4582,5622,6862,8372,10168,12336, %U A242101 14912,18010,21672,26052,31226,37384,44632,53226,63318,75238,89202,105630,124832 %N A242101 Number of conjugacy classes of the symmetric group S_n when conjugating only by even permutations. %F A242101 For n >=2, a(n) = A000041(n) + A000700(n) = 2*A046682(n) [by a formula in A046682]. - _Eric M. Schmidt_, Aug 23 2014 %o A242101 (GAP) List([1..11], n->Size(OrbitsDomain(AlternatingGroup(IsPermGroup, n), SymmetricGroup(IsPermGroup, n), \^))); %Y A242101 Cf. A242099 (by dihedral group), A000041 (by symmetric group itself), A061417 (by cyclic group). %Y A242101 Cf. A046682. %K A242101 nonn %O A242101 1,2 %A A242101 _Attila Egri-Nagy_, Aug 14 2014 %E A242101 More terms from _Eric M. Schmidt_, Aug 23 2014