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 A172961 #8 Apr 18 2020 22:26:58 %S A172961 1,3139,19546975,171475190227,1846780916614531,22800663583664571781, %T A172961 310323674631037864285609,4543765474410728783088589075, %U A172961 70417932475495769964322670258947,1142003787585101049672484911221507209 %N A172961 Number of n X 9 0..9 arrays with row sums 9 and column sums n. %H A172961 R. H. Hardin, <a href="/A172961/b172961.txt">Table of n, a(n) for n=1..24</a> %Y A172961 Column k=9 of A333901. %K A172961 nonn %O A172961 1,2 %A A172961 _R. H. Hardin_, Feb 06 2010