A302625 - OEIS

%I #4 Apr 10 2018 19:14:28

%S 8,81,71,130,251,497,1051,2274,4999,10972,24236,53509,118285,261369,

%T 577860,1277311,2823836,6242370,13800217,30507579,67443317,149095642,

%U 329605433,728654642,1610832508,3561051759,7872390883,17403425209

%N Number of 4Xn 0..1 arrays with every element equal to 0, 1, 2 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

%C Row 4 of A302623.

%H R. H. Hardin, <a href="/A302625/b302625.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +2*a(n-2) +2*a(n-3) +a(n-4) -4*a(n-5) -a(n-6) -2*a(n-7) +2*a(n-8) for n>11

%e Some solutions for n=5

%e ..0..1..0..1..0. .0..0..1..0..0. .0..0..1..0..0. .0..1..0..0..1

%e ..0..1..1..1..0. .1..0..1..0..1. .1..1..0..1..1. .0..1..0..1..1

%e ..0..1..0..1..0. .1..0..1..0..1. .0..1..0..1..0. .1..1..0..1..0

%e ..0..1..0..1..0. .1..0..1..0..0. .0..1..0..1..0. .1..0..0..1..0

%Y Cf. A302623.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 10 2018