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 A201536 #7 Jul 22 2025 16:17:29 %S A201536 9,175,3354,91425,2446147,61807736,1408677515,28646055184, %T A201536 523398227137,8686880778087,132361720458239,1868645862989467, %U A201536 24631940812325029,305098771555173655,3569810381726216867,39630824798203404663 %N A201536 Number of nX5 0..2 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor. %C A201536 Column 5 of A201539 %H A201536 R. H. Hardin, <a href="/A201536/b201536.txt">Table of n, a(n) for n = 1..160</a> %e A201536 Some solutions for n=4 %e A201536 ..0..0..2..2..2....0..1..1..1..2....0..1..1..1..2....0..0..0..0..1 %e A201536 ..1..1..0..1..1....0..1..1..2..2....0..1..2..2..2....0..0..2..2..1 %e A201536 ..2..2..0..1..1....1..0..1..1..1....2..1..1..2..2....0..2..0..0..1 %e A201536 ..2..2..1..1..1....1..0..2..2..2....2..2..1..1..1....2..2..0..0..0 %K A201536 nonn %O A201536 1,1 %A A201536 _R. H. Hardin_ Dec 02 2011