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 A274725 #4 Jul 03 2016 20:00:36 %S A274725 41,384,1300,10368,84948,687248,5634776,45990340,375845052,3070055916, %T A274725 25083639844,204917982144,1674151403908,13677241018800, %U A274725 111739565720152,912879351011812,7457971359536024,60929501956856368,497776886832382136 %N A274725 Number of nX5 0..2 arrays with no element equal to any value at offset (-1,-2) (-2,-1) or (-1,0) and new values introduced in order 0..2. %C A274725 Column 5 of A274728. %H A274725 R. H. Hardin, <a href="/A274725/b274725.txt">Table of n, a(n) for n = 1..210</a> %F A274725 Empirical: a(n) = 3*a(n-1) +33*a(n-2) +66*a(n-3) +94*a(n-4) -115*a(n-5) -155*a(n-6) -255*a(n-7) +236*a(n-8) +152*a(n-9) +61*a(n-10) -213*a(n-11) +90*a(n-12) -5*a(n-13) +13*a(n-14) -4*a(n-15) for n>19 %e A274725 Some solutions for n=4 %e A274725 ..0..1..0..2..0. .0..1..0..2..1. .0..1..2..0..0. .0..1..0..1..1 %e A274725 ..2..0..1..0..1. .2..0..2..0..2. .1..2..1..2..1. .2..0..2..0..2 %e A274725 ..0..2..0..2..0. .0..2..0..2..0. .0..1..2..1..2. .1..2..0..2..0 %e A274725 ..2..0..2..0..2. .2..0..1..1..2. .2..0..1..0..1. .2..0..2..1..1 %Y A274725 Cf. A274728. %K A274725 nonn %O A274725 1,1 %A A274725 _R. H. Hardin_, Jul 03 2016