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 A172894 #10 Apr 26 2015 19:08:18 %S A172894 1,1,7,406,132724,164176640,602351808741,5562418293759978, %T A172894 114601242382721619224,4801114002903931560293544, %U A172894 379957050243738294456427057200,53499490664883668314419655562118240 %N A172894 Number of n X n 0..6 arrays with row sums 6 and column sums 6. %H A172894 R. H. Hardin, <a href="/A172894/b172894.txt">Table of n, a(n) for n = 0..25</a> %Y A172894 Column k=6 of A257493. %K A172894 nonn %O A172894 0,3 %A A172894 _R. H. Hardin_, Feb 06 2010