A302636 - OEIS

%I #4 Apr 10 2018 19:33:02

%S 4,6,8,14,25,47,83,150,269,488,876,1581,2845,5133,9242,16661,30012,

%T 54094,97457,175631,316451,570258,1027529,1851592,3336392,6012049,

%U 10833241,19520945,35175378,63384029,114213840,205806518,370850169,668249367

%N Number of 3Xn 0..1 arrays with every element equal to 0, 1, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

%C Row 3 of A302635.

%H R. H. Hardin, <a href="/A302636/b302636.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=5

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

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

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

%Y Cf. A302635.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 10 2018