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 A172958 #10 Apr 27 2015 11:28:45 %S A172958 1,1,10,1540,2309384,20856798285,842286559093240, %T A172958 123538613356253145400,56272722406349235035916800, %U A172958 70417932475495769964322670258947,219302242655748448462474951981229489200 %N A172958 Number of n X n 0..9 arrays with row sums 9 and column sums 9. %H A172958 R. H. Hardin, <a href="/A172958/b172958.txt">Table of n, a(n) for n = 0..15</a> %Y A172958 Column k=9 of A257493. %K A172958 nonn %O A172958 0,3 %A A172958 _R. H. Hardin_, Feb 06 2010