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 A198183 #7 Jun 02 2025 05:24:07 %S A198183 1,21,148,883,8298,51688,395340,2639341,19059216,135044844,958174742, %T A198183 6800519266,48283678834,342710822044,2431565681788,17263106688089, %U A198183 122543913785532,869732001977147,6173405546650902,43819646823646105 %N A198183 Number of nX6 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4. %C A198183 Every 0 is next to 0 0's, every 1 is next to 1 2'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 A198183 Column 6 of A198185 %H A198183 R. H. Hardin, <a href="/A198183/b198183.txt">Table of n, a(n) for n = 1..199</a> %e A198183 Some solutions containing all values 0 to 4 for n=4 %e A198183 ..2..1..0..3..0..1....1..2..0..3..0..1....0..2..1..0..3..0....2..1..1..2..1..0 %e A198183 ..1..0..4..0..3..2....0..1..3..0..3..2....1..1..0..4..0..1....1..0..3..0..1..2 %e A198183 ..0..3..0..4..0..1....2..1..0..4..0..1....2..0..3..0..3..2....0..3..0..4..0..1 %e A198183 ..1..2..1..0..3..0....1..0..3..0..3..0....1..1..2..1..0..1....1..2..1..0..3..0 %K A198183 nonn %O A198183 1,2 %A A198183 _R. H. Hardin_ Oct 21 2011