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 A283567 #4 Mar 11 2017 08:13:02 %S A283567 1,26,169,1108,6453,36038,194173,1021432,5275885,26869458,135310457, %T A283567 675163708,3343196861,16447661790,80470971869,391822686752, %U A283567 1899839181365,9177752354378,44190339947417,212148874972196,1015791721800101 %N A283567 Number of nX3 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 A283567 Column 3 of A283572. %H A283567 R. H. Hardin, <a href="/A283567/b283567.txt">Table of n, a(n) for n = 1..210</a> %F A283567 Empirical: a(n) = 10*a(n-1) -27*a(n-2) -4*a(n-3) +89*a(n-4) -106*a(n-5) -85*a(n-6) +228*a(n-7) -60*a(n-8) -192*a(n-9) +144*a(n-10) +64*a(n-11) -64*a(n-12) %e A283567 Some solutions for n=4 %e A283567 ..1..0..0. .1..1..1. .0..1..0. .0..1..1. .0..1..0. .1..1..1. .0..1..0 %e A283567 ..1..1..0. .1..0..0. .0..0..0. .0..0..0. .0..1..1. .0..0..0. .1..0..0 %e A283567 ..1..0..1. .0..0..0. .0..0..1. .1..0..1. .0..0..0. .1..0..1. .1..0..1 %e A283567 ..1..0..1. .1..1..0. .0..1..1. .0..1..1. .0..1..1. .0..0..0. .0..1..0 %Y A283567 Cf. A283572. %K A283567 nonn %O A283567 1,2 %A A283567 _R. H. Hardin_, Mar 11 2017