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Number of nX2 0..1 arrays with every element unequal to 0, 1, 3, 4 or 5 king-move adjacent elements, with upper left element zero.
8

%I #4 May 11 2018 14:21:14

%S 2,5,9,21,57,125,289,741,1737,4045,9969,23861,56217,135965,326849,

%T 776581,1864297,4479085,10691729,25606101,61438777,146972605,

%U 351821409,843331621,2019112457,4833683725,11580336689,27733236341,66402706137

%N Number of nX2 0..1 arrays with every element unequal to 0, 1, 3, 4 or 5 king-move adjacent elements, with upper left element zero.

%C Column 2 of A304355.

%H R. H. Hardin, <a href="/A304349/b304349.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A304355.

%K nonn

%O 1,1

%A _R. H. Hardin_, May 11 2018