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 A229872 #6 Jul 23 2025 05:48:32 %S A229872 247552,923742873,354003288064,36821326171875,1656812779036416, %T A229872 41629349513286507,681576779395104768,8038582007461068429, %U A229872 73160330136500000000,539739832319262606581,3347559386080200916992 %N A229872 Number of 5X5 0..n arrays with corresponding row and column sums equal. %C A229872 Row 5 of A229870 %H A229872 R. H. Hardin, <a href="/A229872/b229872.txt">Table of n, a(n) for n = 1..15</a> %e A229872 Some solutions for n=4 %e A229872 ..0..0..0..0..1....0..0..0..0..0....0..0..0..0..1....0..0..0..0..0 %e A229872 ..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0 %e A229872 ..0..0..3..0..4....0..0..3..2..3....0..0..1..2..4....0..0..0..1..3 %e A229872 ..0..0..1..2..3....0..0..4..3..2....0..0..4..0..1....0..0..2..2..3 %e A229872 ..1..0..3..4..2....0..0..1..4..1....1..0..2..3..1....0..0..2..4..3 %K A229872 nonn %O A229872 1,1 %A A229872 _R. H. Hardin_, Oct 01 2013