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 A275147 #4 Jul 17 2016 16:30:27 %S A275147 365,46656,50000,122368,175120,841536,4055152,19906560,98050624, %T A275147 485275472,2393975472,11827067056,58618143280,290834622960, %U A275147 1442223151168,7149923428256,35460798018688,175959368070992,873276392285488 %N A275147 Number of 7Xn 0..2 arrays with no element equal to any value at offset (-2,-2) (-1,-2) or (0,-1) and new values introduced in order 0..2. %C A275147 Row 7 of A275142. %H A275147 R. H. Hardin, <a href="/A275147/b275147.txt">Table of n, a(n) for n = 1..210</a> %F A275147 Empirical: a(n) = 21*a(n-1) -209*a(n-2) +1330*a(n-3) -6059*a(n-4) +20839*a(n-5) -55739*a(n-6) +118287*a(n-7) -202495*a(n-8) +284119*a(n-9) -331806*a(n-10) +326718*a(n-11) -273224*a(n-12) +193798*a(n-13) -115270*a(n-14) +56258*a(n-15) -21837*a(n-16) +6481*a(n-17) -1404*a(n-18) +210*a(n-19) -20*a(n-20) +a(n-21) for n>27 %e A275147 Some solutions for n=5 %e A275147 ..0..1..0..2..1. .0..1..0..1..0. .0..1..0..1..2. .0..1..0..1..0 %e A275147 ..1..2..1..0..1. .0..2..1..0..1. .1..2..1..0..2. .0..1..2..0..1 %e A275147 ..2..0..2..0..2. .0..2..1..0..2. .1..0..2..0..2. .2..1..2..0..1 %e A275147 ..2..1..0..1..0. .1..0..2..1..2. .2..1..2..1..0. .2..0..1..0..1 %e A275147 ..0..1..0..2..1. .1..0..2..1..0. .0..1..0..2..1. .1..2..1..2..0 %e A275147 ..0..2..1..2..1. .2..1..2..1..0. .0..2..1..0..1. .0..2..0..1..2 %e A275147 ..1..0..2..0..2. .2..1..0..2..1. .2..0..1..0..2. .1..0..2..1..2 %Y A275147 Cf. A275142. %K A275147 nonn %O A275147 1,1 %A A275147 _R. H. Hardin_, Jul 17 2016