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 A196492 #7 Jun 02 2025 04:26:18 %S A196492 1,31,553,7761,123151,1875863,28338246,434666223,6656162368, %T A196492 101518856651,1549818281847,23688276304457,361894920969682, %U A196492 5527193051141256,84429912619066523,1289786041484393709,19702421130556030141 %N A196492 Number of nX7 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,3,0,1,4 for x=0,1,2,3,4. %C A196492 Every 0 is next to 0 2's, every 1 is next to 1 3's, every 2 is next to 2 0's, every 3 is next to 3 1's, every 4 is next to 4 4's %C A196492 Column 7 of A196493 %H A196492 R. H. Hardin, <a href="/A196492/b196492.txt">Table of n, a(n) for n = 1..200</a> %e A196492 Some solutions for n=4 %e A196492 ..1..3..1..0..0..1..0....0..0..0..1..0..0..0....0..0..1..0..0..0..0 %e A196492 ..1..1..0..0..1..3..0....0..0..0..3..1..0..0....1..0..3..1..1..3..1 %e A196492 ..3..1..0..0..1..1..0....0..0..1..1..0..0..0....3..1..1..0..0..1..0 %e A196492 ..1..0..0..1..3..1..0....0..1..3..1..0..0..0....1..0..0..0..0..0..0 %K A196492 nonn %O A196492 1,2 %A A196492 _R. H. Hardin_ Oct 03 2011