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 A172541 #11 Mar 09 2017 06:30:48 %S A172541 0,0,0,0,0,0,1,40320,14398171200,8302816499443200, %T A172541 7722015017013984456000,11649337108041078980732943360, %U A172541 28278447454165011203551734584421120,108738182111446498614705217754614976371200 %N A172541 Number of n X n 0..1 arrays with row sums 7 and column sums 7. %H A172541 R. H. Hardin, <a href="/A172541/b172541.txt">Table of n, a(n) for n=1..23</a> %Y A172541 Column 7 of A008300, Cf. A075754. %K A172541 nonn %O A172541 1,8 %A A172541 _R. H. Hardin_, Feb 06 2010