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 A267727 #5 Aug 12 2016 06:54:16 %S A267727 0,6,6,630,1398,93672,609264,20702760,279681294,7420195854, %T A267727 149049265998,3763960753368,88917911372016 %N A267727 Number of 4Xn arrays containing n copies of 0..4-1 with every element equal to at least one horizontal neighbor and the top left element equal to 0. %C A267727 Row 4 of A267724. %e A267727 Some solutions for n=4 %e A267727 ..0..0..0..0....0..0..3..3....0..0..1..1....0..0..2..2....0..0..2..2 %e A267727 ..2..2..3..3....1..1..3..3....0..0..3..3....1..1..3..3....3..3..3..3 %e A267727 ..2..2..1..1....2..2..0..0....2..2..3..3....0..0..3..3....2..2..0..0 %e A267727 ..1..1..3..3....1..1..2..2....2..2..1..1....1..1..2..2....1..1..1..1 %Y A267727 Cf. A267724. %K A267727 nonn %O A267727 1,2 %A A267727 _R. H. Hardin_, Jan 20 2016