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 A297393 #4 Dec 29 2017 10:54:53 %S A297393 9,69,323,2569,14940,99682,640562,4101278,26607999,170810312, %T A297393 1102871801,7104859427,45791052572,295185451556,1902301744507, %U A297393 12261796238309,79028574384941,509365351856610,3283017190154762,21159928491044181 %N A297393 Number of nX6 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 neighboring 1. %C A297393 Column 6 of A297395. %H A297393 R. H. Hardin, <a href="/A297393/b297393.txt">Table of n, a(n) for n = 1..210</a> %F A297393 Empirical: a(n) = 2*a(n-1) +16*a(n-2) +55*a(n-3) +143*a(n-4) +377*a(n-5) -1022*a(n-6) -1350*a(n-7) -647*a(n-8) -3863*a(n-9) -4798*a(n-10) -4588*a(n-11) +36964*a(n-12) +21604*a(n-13) +14553*a(n-14) +107577*a(n-15) +51945*a(n-16) -52831*a(n-17) -345125*a(n-18) -312451*a(n-19) -218764*a(n-20) -24650*a(n-21) +55508*a(n-22) +98904*a(n-23) +3168*a(n-24) -16128*a(n-25) %e A297393 Some solutions for n=5 %e A297393 ..0..0..0..0..1..1. .0..1..0..1..1..0. .0..1..0..0..0..1. .0..1..1..0..1..0 %e A297393 ..1..1..0..0..0..0. .1..0..0..0..0..0. .1..0..0..0..1..0. .0..0..0..0..0..1 %e A297393 ..0..0..0..1..1..0. .0..0..1..1..0..0. .1..0..0..0..0..0. .0..1..1..0..0..1 %e A297393 ..0..1..0..0..0..0. .0..0..0..0..0..1. .0..1..0..0..0..1. .0..0..0..0..1..0 %e A297393 ..0..0..1..0..1..1. .1..1..0..0..1..0. .0..0..0..0..1..0. .0..1..1..0..0..0 %Y A297393 Cf. A297395. %K A297393 nonn %O A297393 1,1 %A A297393 _R. H. Hardin_, Dec 29 2017