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 A276292 #6 Apr 21 2020 12:48:05 %S A276292 1,4,45,1017,50949,4988145,1073114625,456837553545,427500156271073, %T A276292 794420496019076757,3247016064162495298253 %N A276292 Number of n X n 0..2 arrays with no element equal to any value at offset (-2,-1), (-1,1) or (0,-1) and new values introduced in order 0..2. %C A276292 Diagonal of A276299. %e A276292 Some solutions for n=4 %e A276292 ..0..1..0..2. .0..1..2..1. .0..1..0..1. .0..1..2..0. .0..1..2..1 %e A276292 ..0..2..0..1. .0..1..2..1. .0..2..0..2. .2..0..2..1. .2..1..0..1 %e A276292 ..0..2..0..1. .0..1..2..0. .1..2..0..1. .2..1..2..1. .0..1..0..1 %e A276292 ..1..2..0..2. .2..1..2..1. .0..1..0..1. .2..1..2..0. .0..1..2..1 %Y A276292 Cf. A276299. %K A276292 nonn %O A276292 1,2 %A A276292 _R. H. Hardin_, Aug 28 2016