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 A172662 #6 Oct 15 2023 18:55:22 %S A172662 1,19,5881,115321795,101471705778601,5520471267708881730181, %T A172662 17949532724881770551236183389177, %U A172662 3781994369388530584295658367829503216546371 %N A172662 Number of 2*n X n 0..2 arrays with row sums n and column sums 2*n. %H A172662 R. H. Hardin, <a href="/A172662/b172662.txt">Table of n, a(n) for n=1..10</a> %K A172662 nonn %O A172662 1,2 %A A172662 _R. H. Hardin_, Feb 06 2010