A301879 - OEIS

%I #4 Mar 28 2018 10:54:54

%S 3,10,29,95,289,917,2841,8921,27801,87009,271657,849313,2653273,

%T 8292465,25910729,80972065,253021369,790675217,2470747561,7720841601,

%U 24126677401,75393222129,235594969737,736207657313,2300563919993,7188999803345

%N Number of nX3 0..1 arrays with every element equal to 0, 1 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A301884.

%H R. H. Hardin, <a href="/A301879/b301879.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +6*a(n-2) +2*a(n-3)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A301884.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 28 2018