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 A185431 #7 Jul 22 2025 09:46:30 %S A185431 4370405405266,1297535366114472,209290512833668811, %T A185431 22687513754718781985,1812817799965228636502,112849363355150447528536, %U A185431 5686283998453160141912882,238618763396476742696570337 %N A185431 Number of (n+2)X7 0..7 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order. %C A185431 Column 5 of A185435 %H A185431 R. H. Hardin, <a href="/A185431/b185431.txt">Table of n, a(n) for n = 1..27</a> %e A185431 Some solutions for 4X7 %e A185431 ..0..0..0..0..0..0..1....0..0..0..0..0..0..0....0..0..0..0..0..0..0 %e A185431 ..0..0..0..0..0..0..2....0..0..0..0..0..0..2....0..0..0..0..0..1..5 %e A185431 ..0..0..0..0..0..3..1....0..0..0..0..0..1..2....0..0..0..0..0..4..0 %e A185431 ..0..0..0..0..0..6..2....0..0..0..0..0..2..4....0..0..0..0..0..4..7 %K A185431 nonn %O A185431 1,1 %A A185431 _R. H. Hardin_ Jan 27 2011