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 A274754 #4 Jul 04 2016 10:29:13 %S A274754 32,729,10946,185435,3140840,53680592,920432562,15806543610, %T A274754 271711836855,4671914239590,80354505513874,1382068876451987, %U A274754 23773417216542030,408926400535170333,7034177852486985161,120997474917708497554 %N A274754 Number of 7Xn 0..2 arrays with no element equal to any value at offset (-1,-2) (0,-1) or (-1,0) and new values introduced in order 0..2. %C A274754 Row 7 of A274749. %H A274754 R. H. Hardin, <a href="/A274754/b274754.txt">Table of n, a(n) for n = 1..210</a> %H A274754 R. H. Hardin, <a href="/A274754/a274754.txt">Empirical recurrence of order 80</a> %F A274754 Empirical recurrence of order 80 (see link above) %e A274754 Some solutions for n=4 %e A274754 ..0..1..0..1. .0..1..0..2. .0..1..0..2. .0..1..0..1. .0..1..0..1 %e A274754 ..1..2..1..0. .2..0..1..0. .2..0..1..0. .2..0..1..2. .1..2..1..2 %e A274754 ..2..1..0..1. .0..1..0..1. .0..1..0..1. .0..1..0..1. .2..1..0..1 %e A274754 ..1..0..1..2. .2..0..2..0. .1..0..2..0. .1..2..1..0. .0..2..1..2 %e A274754 ..0..1..2..1. .1..2..0..1. .0..1..0..1. .0..1..2..1. .1..0..2..0 %e A274754 ..1..0..1..0. .0..1..2..0. .1..2..1..2. .1..0..1..2. .0..1..0..2 %e A274754 ..2..1..2..1. .2..0..1..2. .2..0..2..1. .0..1..2..1. .2..0..1..0 %Y A274754 Cf. A274749. %K A274754 nonn %O A274754 1,1 %A A274754 _R. H. Hardin_, Jul 04 2016