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 A068268 #8 Apr 27 2012 17:37:42 %S A068268 1,4641,5554571857,1714419367669298289,136461767759964622690609683537, %T A068268 2801124263786734144622842493797034683405617, %U A068268 14827953377838619886793709359009173477911476430325930106481,20242190237452646688395985657256161903754274932459524235140863308223305109841 %N A068268 1/18 the number of colorings of an n X n square array with 18 colors. %Y A068268 Cf. A068239-A068305, A000332, A002417, A027441, A182368, A182406. %K A068268 nonn %O A068268 1,2 %A A068268 _R. H. Hardin_, Feb 24 2002 %E A068268 a(5)-a(8) from _Alois P. Heinz_, Apr 27 2012