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 A197247 #7 Jun 02 2025 04:48:43 %S A197247 3,40,110,780,5062,31276,213912,1244680,8149652,54813300,363207297, %T A197247 2334210952,15099425049,99496688244,657733281792,4291822021778, %U A197247 27959094118746,183056501656614,1201021999376817,7872982494463940 %N A197247 Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,0,1,1,1 for x=0,1,2,3,4. %C A197247 Every 0 is next to 0 0's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's %C A197247 Column 5 of A197250 %H A197247 R. H. Hardin, <a href="/A197247/b197247.txt">Table of n, a(n) for n = 1..210</a> %e A197247 Some solutions containing all values 0 to 4 for n=4 %e A197247 ..0..1..3..1..0....1..0..2..1..0....1..0..2..1..0....0..1..1..2..0 %e A197247 ..1..4..1..4..1....3..1..1..4..1....3..1..1..4..1....1..3..0..1..1 %e A197247 ..2..1..0..1..2....1..3..0..1..2....1..1..0..1..1....3..1..1..4..1 %e A197247 ..0..2..1..1..0....0..1..1..2..0....0..2..1..2..0....1..0..1..1..0 %K A197247 nonn %O A197247 1,1 %A A197247 _R. H. Hardin_ Oct 12 2011