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 A196215 #7 Jun 02 2025 04:19:18 %S A196215 9,189,1217,14605,173216,1937895,21716929,244152037,2771090244, %T A196215 31410926798,354585313303,4007921508273,45388862660525, %U A196215 513791891452149,5811758649045041,65752943364665551,744175679426127501 %N A196215 Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,1,2,4 for x=0,1,2,3,4. %C A196215 Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 2's, every 4 is next to 4 4's %C A196215 Column 5 of A196218 %H A196215 R. H. Hardin, <a href="/A196215/b196215.txt">Table of n, a(n) for n = 1..200</a> %e A196215 Some solutions for n=4 %e A196215 ..1..1..0..1..1....1..0..0..1..1....1..0..1..1..2....1..1..0..1..2 %e A196215 ..0..1..2..2..0....2..1..2..2..0....1..1..2..0..1....0..1..2..1..1 %e A196215 ..0..1..1..1..2....0..1..1..1..2....0..1..2..0..1....1..1..2..0..0 %e A196215 ..1..1..0..0..1....1..2..0..0..1....0..1..1..0..1....1..0..1..1..1 %K A196215 nonn %O A196215 1,1 %A A196215 _R. H. Hardin_ Sep 29 2011