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 A302961 #4 Apr 16 2018 11:52:24 %S A302961 8,105,786,6206,49521,395493,3157171,25208524,201291251,1607313882, %T A302961 12834468946,102483891605,818339663167,6534489434899,52178280478900, %U A302961 416646642993447,3326948061363744,26565877137213190,212130102108362955 %N A302961 Number of nX4 0..1 arrays with every element equal to 0, 1, 2, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302961 Column 4 of A302965. %H A302961 R. H. Hardin, <a href="/A302961/b302961.txt">Table of n, a(n) for n = 1..210</a> %F A302961 Empirical: a(n) = 10*a(n-1) -7*a(n-2) -65*a(n-3) -84*a(n-4) +100*a(n-5) +541*a(n-6) +1363*a(n-7) -386*a(n-8) -2958*a(n-9) -6187*a(n-10) +2238*a(n-11) +4139*a(n-12) +7410*a(n-13) -4494*a(n-14) +2183*a(n-15) -3163*a(n-16) +1920*a(n-17) -1968*a(n-18) +256*a(n-19) for n>20 %e A302961 Some solutions for n=5 %e A302961 ..0..1..0..0. .0..0..1..0. .0..0..1..0. .0..1..0..1. .0..0..1..0 %e A302961 ..0..1..0..0. .0..0..1..0. .1..0..1..1. .0..1..0..0. .0..1..0..0 %e A302961 ..1..1..0..0. .0..0..1..1. .1..1..1..0. .0..1..0..1. .1..1..0..1 %e A302961 ..1..1..0..0. .1..1..0..1. .1..0..1..0. .1..1..0..1. .1..0..0..0 %e A302961 ..0..0..1..1. .0..1..0..0. .0..1..0..0. .1..0..1..1. .0..1..1..0 %Y A302961 Cf. A302965. %K A302961 nonn %O A302961 1,1 %A A302961 _R. H. Hardin_, Apr 16 2018