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 A278185 #4 Nov 14 2016 22:29:53 %S A278185 0,136,13012,1075258,91270219,7737459027,656008970388,55620335387114, %T A278185 4715820197535009,399835065589298715,33900377809514573711, %U A278185 2874274212652455298123,243697940183994435905588 %N A278185 Number of nX4 0..3 arrays with every element plus 1 mod 4 equal to some element at offset (-1,-1) (-1,0) (-1,1) (0,-1) (0,1) or (1,0), with upper left element zero. %C A278185 Column 4 of A278188. %H A278185 R. H. Hardin, <a href="/A278185/b278185.txt">Table of n, a(n) for n = 1..210</a> %e A278185 Some solutions for n=3 %e A278185 ..0..2..3..1. .0..1..2..3. .0..1..2..0. .0..1..2..0. .0..3..0..2 %e A278185 ..1..1..0..2. .0..0..2..0. .2..0..3..1. .3..2..3..1. .1..2..1..3 %e A278185 ..0..0..1..3. .3..2..1..1. .3..1..0..2. .1..2..1..0. .3..0..2..1 %Y A278185 Cf. A278188. %K A278185 nonn %O A278185 1,2 %A A278185 _R. H. Hardin_, Nov 14 2016