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A305582
Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 7 or 8 king-move adjacent elements, with upper left element zero.
1
8, 5, 8, 15, 38, 102, 247, 617, 1559, 3892, 9739, 24416, 61132, 153073, 383397, 960157, 2404528, 6021899, 15081066, 37768418, 94586143, 236878625, 593231091, 1485669328, 3720663535, 9317911688, 23335483576, 58440647945, 146356910517
OFFSET
1,1
COMMENTS
Column 4 of A305586.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +2*a(n-2) +5*a(n-3) -2*a(n-5) -4*a(n-6) for n>8
EXAMPLE
Some solutions for n=5
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..1..1..1
..0..0..0..0. .0..0..1..0. .0..0..1..0. .0..1..0..0. .1..0..1..1
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .1..1..1..1
..0..1..1..0. .0..0..0..0. .0..0..1..0. .0..1..0..0. .1..1..0..1
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .1..1..1..0
CROSSREFS
Cf. A305586.
Sequence in context: A198136 A328942 A308743 * A144454 A074071 A100126
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 05 2018
STATUS
approved