A317520 - OEIS

%I #4 Jul 30 2018 11:36:54

%S 4,32,248,1921,14892,115446,894961,6937925,53784248,416946757,

%T 3232258602,25057145775,194248243009,1505853070853,11673688450775,

%U 90496878270178,701550757601700,5438568433511460,42160921765806133,326840297382217310

%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 3, 4, 5, 6 or 8 king-move adjacent elements, with upper left element zero.

%C Column 3 of A317525.

%H R. H. Hardin, <a href="/A317520/b317520.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 8*a(n-1) -2*a(n-2) +a(n-3) -3*a(n-4)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A317525.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jul 30 2018