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 A283575 #4 Mar 11 2017 08:20:14 %S A283575 0,68,1108,6812,67892,509952,3890056,29428836,214600036,1561753984, %T A283575 11203805186,79697223948,563151495500,3952776211644,27603742610922, %U A283575 191869394908352,1328251534591608,9162408587486912,63001467075539154 %N A283575 Number of 4Xn 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element. %C A283575 Row 4 of A283572. %H A283575 R. H. Hardin, <a href="/A283575/b283575.txt">Table of n, a(n) for n = 1..210</a> %F A283575 Empirical: a(n) = 4*a(n-1) +34*a(n-2) +48*a(n-3) -561*a(n-4) -2288*a(n-5) -5234*a(n-6) -5692*a(n-7) -8384*a(n-8) +4044*a(n-9) -3814*a(n-10) +27880*a(n-11) -6865*a(n-12) +31280*a(n-13) -24250*a(n-14) +14500*a(n-15) -21025*a(n-16) %e A283575 Some solutions for n=4 %e A283575 ..0..1..0..1. .0..1..0..1. .0..1..0..1. .1..0..1..0. .0..1..0..1 %e A283575 ..0..1..1..1. .0..0..1..0. .0..0..0..1. .1..0..0..1. .1..1..0..0 %e A283575 ..0..1..0..1. .0..0..0..0. .1..0..0..1. .0..1..0..0. .0..1..0..1 %e A283575 ..0..1..0..1. .1..1..0..0. .1..0..1..1. .0..0..1..0. .0..1..0..1 %Y A283575 Cf. A283572. %K A283575 nonn %O A283575 1,2 %A A283575 _R. H. Hardin_, Mar 11 2017