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 A197536 #7 Jun 02 2025 04:58:57 %S A197536 25,361,14085,423085,14056707,454280983,14991391782,493785636151, %T A197536 16343961543732,541269402906501,17943273862788427,595019891173209941, %U A197536 19736497896904338854,654726724059190203302,21721092108797190824889 %N A197536 Number of nX7 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,0,1,0,0 for x=0,1,2,3,4. %C A197536 Every 0 is next to 0 2's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 0's %C A197536 Column 7 of A197537 %H A197536 R. H. Hardin, <a href="/A197536/b197536.txt">Table of n, a(n) for n = 1..156</a> %e A197536 Some solutions containing all values 0 to 4 for n=4 %e A197536 ..0..0..3..0..3..0..0....0..3..0..3..0..1..2....1..0..0..0..0..1..2 %e A197536 ..0..3..0..0..0..0..0....3..0..0..0..0..1..1....1..3..0..3..1..1..1 %e A197536 ..1..1..0..4..0..0..3....0..4..0..3..1..1..0....0..0..4..0..3..0..0 %e A197536 ..2..1..0..0..0..3..0....0..0..3..0..1..1..0....0..0..0..3..0..0..0 %K A197536 nonn %O A197536 1,1 %A A197536 _R. H. Hardin_ Oct 16 2011