A303956 - OEIS

%I #4 May 03 2018 12:43:43

%S 4,5,11,22,49,119,287,664,1563,3716,8788,20753,49077,116121,274644,

%T 649499,1536206,3633554,8594035,20326437,48076235,113710340,268947851,

%U 636115892,1504543784,3558552569,8416699677,19907205269,47084589648

%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 5 king-move adjacent elements, with upper left element zero.

%C Column 3 of A303961.

%H R. H. Hardin, <a href="/A303956/b303956.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A303961.

%K nonn

%O 1,1

%A _R. H. Hardin_, May 03 2018