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 A029809 #10 Dec 15 2017 17:34:48
%S A029809 1,52,5133,656880,97772875,16032938340,2812609211657,518547356184000,
%T A029809 99318297529004400,19605670296090989500,3966181169996511862429,
%U A029809 818782296743542722132528,171938262068874336023196923
%N A029809 Number of Lyndon words (aperiodic necklaces) with 4n beads of 4 colors, n beads of each color. One color labeled, the other 3 unlabeled.
%H A029809 <a href="/index/Lu#Lyndon">Index entries for sequences related to Lyndon words</a>
%F A029809 1/(24n) * sum over d|n of {mu(n/d) * (4d)! / d!^4}.
%o A029809 (PARI) for(n=1,23,print(1/(24*n)*sumdiv(n,d,moebius(n/d)*(4*d)!/d!^4)))
%Y A029809 Inverse Witt transform of A006179.
%K A029809 nonn
%O A029809 1,2
%A A029809 Lionel Levine (levine(AT)ultranet.com)
%E A029809 More terms from _Jason Earls_, Aug 31 2001
%E A029809 Edited by _Christian G. Bower_, Aug 29 2002