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 A221198 #8 Apr 25 2023 15:29:07 %S A221198 8,720,58700,4984812,433687328,38397901048,3437301520640, %T A221198 309729304158392,28014137861507600,2539060159927062472, %U A221198 230384024072002424484,20916257751298954797560,1899514293467279631162576 %N A221198 Number of n X 5 arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, with no occupancy greater than 2. %C A221198 Column 5 of A221200. %H A221198 R. H. Hardin, <a href="/A221198/b221198.txt">Table of n, a(n) for n = 1..15</a> %e A221198 Some solutions for n=3 %e A221198 ..1..1..0..1..0....0..0..0..2..1....0..2..2..1..1....1..1..1..2..1 %e A221198 ..0..2..2..2..0....0..2..2..2..1....1..2..1..1..0....0..2..1..0..0 %e A221198 ..1..1..1..2..1....0..1..2..2..0....0..2..0..1..1....1..2..0..2..1 %Y A221198 Cf. A221200. %K A221198 nonn %O A221198 1,1 %A A221198 _R. H. Hardin_, Jan 04 2013