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 A186167 #6 Jul 22 2025 10:17:27 %S A186167 97,677283,1610684397,4840082975532,13435825601048421, %T A186167 38514280297010210802 %N A186167 1/4 the number of nX8 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors. %C A186167 Column 8 of A186168 %e A186167 Some solutions for 3X8 with a(1,1)=0 %e A186167 ..0..0..0..0..2..1..1..0....0..0..0..0..3..0..3..3....0..0..0..0..0..3..3..0 %e A186167 ..0..1..1..2..2..3..1..0....0..1..1..0..3..0..0..3....0..1..1..2..2..1..0..0 %e A186167 ..0..0..0..0..0..3..3..0....0..0..0..0..3..3..0..0....0..0..0..0..2..1..3..3 %K A186167 nonn %O A186167 1,1 %A A186167 _R. H. Hardin_ Feb 13 2011