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A316948
Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.
1
1, 25, 160, 1240, 9417, 71505, 543155, 4125662, 31337363, 238029974, 1808010056, 13733145621, 104313185951, 792334186609, 6018351922536, 45713741090407, 347228967561412, 2637455457327040, 20033384133349773, 152168059831839593
OFFSET
1,2
COMMENTS
Column 3 of A316953.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) +10*a(n-2) +15*a(n-3) +8*a(n-4) +3*a(n-5) +a(n-6) +2*a(n-7)
EXAMPLE
Some solutions for n=5
..0..0..1. .0..1..0. .0..1..1. .0..1..0. .0..1..0. .0..1..0. .0..1..1
..1..0..1. .0..0..0. .0..0..0. .0..0..1. .0..0..1. .0..1..1. .0..0..0
..1..1..1. .0..1..0. .0..0..1. .1..0..0. .1..1..1. .1..1..1. .0..0..1
..0..1..0. .1..0..0. .0..1..0. .1..0..0. .1..1..1. .0..1..0. .1..1..0
..1..1..0. .0..1..0. .1..1..1. .0..0..1. .0..0..1. .0..0..0. .0..1..1
CROSSREFS
Cf. A316953.
Sequence in context: A049523 A232000 A260046 * A139729 A317728 A125335
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 17 2018
STATUS
approved