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 A074651 #6 Mar 30 2012 17:37:12
%S A074651 6,42,558,8640,151350,2858562,57010422,1183184640,25319269980,
%T A074651 555099603450,12411545042094,282060978777792,6498315236374338,
%U A074651 151469476107975354,3566331985691591550,84709091524784348160
%N A074651 (1/n) * sum over d|n of {mu(n/d) * (3d)! / d!^3}.
%H A074651 <a href="/index/Lu#Lyndon">Index entries for sequences related to Lyndon words</a>
%Y A074651 Inverse Witt transform of A006174. a(n) = A029808(n)*6. a(n) = A074655(n)*3.
%K A074651 nonn
%O A074651 1,1
%A A074651 _Christian G. Bower_, Aug 29 2002