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A304128 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3 or 6 king-move adjacent elements, with upper left element zero. 1

%I

%S 3,7,9,19,33,53,89,155,261,439,749,1271,2149,3647,6189,10487,17781,

%T 30159,51133,86695,147013,249279,422669,716695,1215253,2060591,

%U 3493981,5924487,10045669,17033631,28882605,48973943,83041205,140806415,238754301

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

%C Column 3 of A304133.

%H R. H. Hardin, <a href="/A304128/b304128.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A304133.

%K nonn

%O 1,1

%A _R. H. Hardin_, May 07 2018

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Last modified February 5 12:47 EST 2023. Contains 360084 sequences. (Running on oeis4.)