A304599 - OEIS

%I #4 May 15 2018 13:28:10

%S 4,5,13,23,53,131,330,793,1930,4765,11686,28627,70237,172374,422930,

%T 1037573,2545757,6246392,15325889,37602947,92261907,226372036,

%U 555420895,1362767425,3343655704,8203918429,20128946224,49387923264,121177087505

%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 5 or 6 king-move adjacent elements, with upper left element zero.

%C Column 3 of A304604.

%H R. H. Hardin, <a href="/A304599/b304599.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +2*a(n-2) +4*a(n-3) +2*a(n-4) -2*a(n-5) -7*a(n-6) -6*a(n-7) for n>10

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A304604.

%K nonn

%O 1,1

%A _R. H. Hardin_, May 15 2018