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 A196808 #7 Jun 02 2025 04:34:44 %S A196808 1,99,1468,52291,1730105,46685074,1436535356,42144649101, %T A196808 1242942835600,36966191677933,1095659240954513,32430161990804370, %U A196808 960817109357914432,28466699840871876758,843388951593615572344,24985495292021432741463 %N A196808 Number of nX7 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,2,3,0,1 for x=0,1,2,3,4. %C A196808 Every 0 is next to 0 4's, every 1 is next to 1 2's, every 2 is next to 2 3's, every 3 is next to 3 0's, every 4 is next to 4 1's %C A196808 Column 7 of A196809 %H A196808 R. H. Hardin, <a href="/A196808/b196808.txt">Table of n, a(n) for n = 1..200</a> %e A196808 Some solutions for n=4 %e A196808 ..0..0..0..0..0..0..0....0..3..0..3..0..0..0....0..0..3..0..0..0..0 %e A196808 ..0..2..3..0..3..0..3....3..0..0..0..0..0..0....0..0..0..0..3..3..0 %e A196808 ..0..3..0..3..2..0..0....0..3..2..3..0..0..3....3..0..3..3..0..0..3 %e A196808 ..0..0..3..0..0..3..0....0..0..1..0..0..3..0....0..3..0..0..0..3..0 %K A196808 nonn %O A196808 1,2 %A A196808 _R. H. Hardin_ Oct 06 2011