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 A068272 #12 Jun 25 2017 17:12:20 %S A068272 1,36,6588,6169500,29607951492,728359861595076,91850117930957987604, %T A068272 59375832328440271451653884,196759041550650648492160100067468, %U A068272 3342365125469959463321258123750822068332,291049545090789051667036543236086657649935910108 %N A068272 1/5 the number of colorings of an n X n rhombic hexagonal array with 5 colors. %C A068272 Terms for rhombic- and staggered- hexagonal arrays are the same for n in 1..4. %Y A068272 Cf. A068239-A068305, A000332, A002417, A027441, A212162, A212163. %K A068272 nonn %O A068272 1,2 %A A068272 _R. H. Hardin_, Feb 24 2002 %E A068272 a(8)-a(9) from _Alois P. Heinz_, May 02 2012 %E A068272 a(10)-a(11) from _Andrew Howroyd_, Jun 25 2017