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 A197315 #7 Jun 02 2025 04:50:35 %S A197315 4,6,79,790,4780,24704,189212,1400102,8813744,62844698,436492213, %T A197315 3010736948,20777197101,144191070226,998239321771,6903357295660, %U A197315 47811537748912,330940337259970,2291691748249353,15860451380186238 %N A197315 Number of nX6 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,1,1,0,0 for x=0,1,2,3,4. %C A197315 Every 0 is next to 0 0's, every 1 is next to 1 1'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 A197315 Column 6 of A197317 %H A197315 R. H. Hardin, <a href="/A197315/b197315.txt">Table of n, a(n) for n = 1..210</a> %e A197315 Some solutions containing all values 0 to 4 for n=4 %e A197315 ..2..1..1..0..3..0....0..3..0..3..0..1....0..1..0..1..1..2....1..1..2..1..1..0 %e A197315 ..1..2..0..4..0..1....1..0..4..0..3..1....2..1..3..0..2..1....0..3..0..3..0..1 %e A197315 ..1..0..4..0..2..1....1..2..0..3..0..2....1..2..0..4..0..1....3..0..4..0..2..1 %e A197315 ..0..3..0..1..1..2....2..1..1..2..1..1....1..0..3..0..3..0....0..3..0..1..1..2 %K A197315 nonn %O A197315 1,1 %A A197315 _R. H. Hardin_ Oct 13 2011