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 A202557 #7 Jul 22 2025 16:39:09 %S A202557 6,73,824,9325,103806,1126437,12176148,130217215,1384437590, %T A202557 14638759530,153859811582,1612968122563,16850540584514, %U A202557 175613681682972,1826081927556004,18940152569016323,196169872012941802 %N A202557 Number of nX5 0,1 arrays with the row and column sums nondecreasing. %C A202557 Column 5 of A202560 %H A202557 R. H. Hardin, <a href="/A202557/b202557.txt">Table of n, a(n) for n = 1..24</a> %e A202557 Some solutions for n=4 %e A202557 ..0..0..0..1..1....0..0..0..0..1....0..0..0..1..1....0..0..0..1..1 %e A202557 ..1..1..0..0..0....0..1..1..0..0....1..0..0..1..1....0..1..0..1..1 %e A202557 ..0..1..1..0..0....1..0..0..0..1....1..1..1..0..0....1..0..1..1..0 %e A202557 ..1..0..1..1..1....0..0..0..1..1....0..1..1..1..1....1..1..1..0..1 %K A202557 nonn %O A202557 1,1 %A A202557 _R. H. Hardin_ Dec 21 2011