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 A196699 #8 Jun 02 2025 04:31:24 %S A196699 1,11,207,16676,4114365,3444722540,9630587515529,90075372757265811 %N A196699 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,1,0,4,2 for x=0,1,2,3,4. %C A196699 Every 0 is next to 0 3's, every 1 is next to 1 1's, every 2 is next to 2 0's, every 3 is next to 3 4's, every 4 is next to 4 2's %C A196699 Diagonal of A196707 %e A196699 Some solutions for n=4 %e A196699 ..0..2..0..2....2..0..0..0....2..0..1..0....0..0..0..0....0..2..0..2 %e A196699 ..2..1..0..0....0..1..1..0....0..0..1..0....2..0..0..0....0..1..1..0 %e A196699 ..0..1..0..1....0..2..0..0....0..0..0..1....2..0..0..0....1..2..0..0 %e A196699 ..0..0..0..1....0..1..1..0....1..1..0..1....0..2..2..0....1..0..0..2 %K A196699 nonn %O A196699 1,2 %A A196699 _R. H. Hardin_ Oct 05 2011