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 A198184 #7 Jun 02 2025 05:24:11 %S A198184 3,56,395,3485,48958,395340,4522496,41084248,441157382,4292509761, %T A198184 44051823241,438360876506,4438621935572,44610898968447, %U A198184 449562512780134,4527350842044875,45564682527974566,459054827920170371 %N A198184 Number of nX7 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4. %C A198184 Every 0 is next to 0 0's, every 1 is next to 1 2'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 A198184 Column 7 of A198185 %H A198184 R. H. Hardin, <a href="/A198184/b198184.txt">Table of n, a(n) for n = 1..73</a> %e A198184 Some solutions containing all values 0 to 4 for n=4 %e A198184 ..1..2..1..0..1..1..0....2..1..0..3..0..3..0....1..0..3..0..3..0..1 %e A198184 ..0..3..0..1..2..2..1....1..0..1..0..4..0..3....2..1..0..4..0..3..2 %e A198184 ..1..0..4..0..3..0..1....1..2..2..3..0..3..0....0..1..3..0..3..0..1 %e A198184 ..2..1..0..3..0..1..2....0..1..1..0..1..2..1....1..2..0..1..2..1..0 %K A198184 nonn %O A198184 1,1 %A A198184 _R. H. Hardin_ Oct 21 2011