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Number of nX4 0..1 arrays with every element equal to 0, 1 or 4 horizontally or vertically adjacent elements, with upper left element zero.
1

%I #4 Mar 25 2018 11:26:05

%S 5,6,9,13,24,45,89,182,373,773,1604,3333,6933,14422,30009,62445,

%T 129944,270413,562729,1171046,2436965,5071365,10553604,21962245,

%U 45703845,95110566,197926889,411889613,857150104,1783745645,3712008569,7724760342

%N Number of nX4 0..1 arrays with every element equal to 0, 1 or 4 horizontally or vertically adjacent elements, with upper left element zero.

%C Column 4 of A301662.

%H R. H. Hardin, <a href="/A301658/b301658.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -2*a(n-4) +a(n-5)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A301662.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 25 2018