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 A186913 #7 Jul 22 2025 10:35:08 %S A186913 44902749582723,13921822487031205,2169936652932512523, %T A186913 219019175194540430058,15954040054059557650482, %U A186913 893383694291331850798966,40128119810449322920431346,1491377073810394581396929600 %N A186913 Number of (n+2)X9 0..6 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order. %C A186913 Column 7 of A186915 %H A186913 R. H. Hardin, <a href="/A186913/b186913.txt">Table of n, a(n) for n = 1..9</a> %e A186913 Some solutions for 4X9 %e A186913 ..0..0..0..0..0..0..0..0..6....0..0..0..0..0..0..0..0..5 %e A186913 ..0..0..0..0..0..0..0..2..3....0..0..0..0..0..0..0..0..5 %e A186913 ..0..0..0..0..0..0..0..4..2....0..0..0..0..0..0..0..1..1 %e A186913 ..0..0..0..0..0..0..0..5..2....0..0..0..0..0..0..0..1..6 %K A186913 nonn %O A186913 1,1 %A A186913 _R. H. Hardin_ Feb 28 2011