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 A068270 #9 Apr 27 2012 17:39:57 %S A068270 1,6517,13841287219,9580458187250990407, %T A068270 2161111220298293067819628379911, %U A068270 158872597397775739573835110149847235229271675,3806290340846629510463844992746098005507806101928649895595171,29719114772241665792629546781476756531800106771541628945462624575440369135473679 %N A068270 1/20 the number of colorings of an n X n square array with 20 colors. %Y A068270 Cf. A068239-A068305, A000332, A002417, A027441, A182368, A182406. %K A068270 nonn %O A068270 1,2 %A A068270 _R. H. Hardin_, Feb 24 2002 %E A068270 a(5)-a(8) from _Alois P. Heinz_, Apr 27 2012