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 A275232 #4 Jul 20 2016 18:31:40 %S A275232 32,404,8134,164645,3334854,67550874,1368326231,27717164160, %T A275232 561446064338,11372797129197,230370331746218,4666441245648374, %U A275232 94524645450606455,1914715759242977500,38784979537110927630,785638615177198244373 %N A275232 Number of 7Xn 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,1) or (-1,0) and new values introduced in order 0..2. %C A275232 Row 7 of A275228. %H A275232 R. H. Hardin, <a href="/A275232/b275232.txt">Table of n, a(n) for n = 1..210</a> %F A275232 Empirical: a(n) = 20*a(n-1) +57*a(n-2) -1206*a(n-3) +3096*a(n-4) +2306*a(n-5) -16957*a(n-6) +20440*a(n-7) -7755*a(n-8) for n>9 %e A275232 Some solutions for n=4 %e A275232 ..0..1..0..2. .0..1..0..2. .0..0..0..1. .0..1..0..0. .0..1..0..0 %e A275232 ..1..0..1..1. .2..0..1..0. .1..2..1..0. .2..2..1..2. .1..2..1..2 %e A275232 ..0..2..0..2. .0..1..0..1. .2..1..2..1. .0..1..2..1. .2..1..2..1 %e A275232 ..2..0..2..0. .2..0..2..0. .1..2..1..0. .1..0..0..2. .1..2..1..2 %e A275232 ..0..2..0..2. .0..2..0..1. .2..1..2..1. .2..1..2..1. .2..1..2..1 %e A275232 ..2..0..2..0. .1..0..2..0. .1..2..1..2. .1..2..1..2. .1..2..1..0 %e A275232 ..1..2..1..1. .0..1..0..1. .2..1..2..1. .2..1..0..1. .0..0..0..1 %Y A275232 Cf. A275228. %K A275232 nonn %O A275232 1,1 %A A275232 _R. H. Hardin_, Jul 20 2016