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 A255516 #11 Mar 12 2015 12:19:25 %S A255516 1,1,2,3,7,13,29,53,126,258,602,1250,3031,6703,16367,36698,91731, %T A255516 214315,542225,1284284,3305371,8063704,21017382,51961767,137324923, %U A255516 347282636,928913378,2379051372,6439629060,16796126329,45974995358,121341267340,335665581851 %N A255516 a(n) = A239839(n)/n! where A239839(n) is the number of ordered pairs of permutation functions on n elements where f(f(f(x))) = g(f(g(x))). %C A255516 The fact that A239839(n) is a multiple of n! follows from a general result in group theory due to Solomon. %H A255516 Hiroaki Yamanouchi, <a href="/A255516/b255516.txt">Table of n, a(n) for n = 0..60</a> %H A255516 L. Solomon, <a href="http://dx.doi.org/10.1007/BF01899292">The solutions of equations in groups</a>, Arch. Math., V.20. no.3, (1969) 241-247. %Y A255516 Cf. A239839. %K A255516 nonn %O A255516 0,3 %A A255516 _Paul Boddington_, Feb 24 2015 %E A255516 a(14)-a(32) from _Hiroaki Yamanouchi_, Mar 12 2015