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A305240
Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 4 or 8 king-move adjacent elements, with upper left element zero.
1
4, 12, 18, 32, 86, 158, 343, 721, 1520, 3228, 6773, 14334, 30273, 63871, 134918, 284843, 601453, 1270011, 2681563, 5662260, 11955917, 25245070, 53305555, 112555500, 237663066, 501829940, 1059622929, 2237413464, 4724339318
OFFSET
1,1
COMMENTS
Column 3 of A305245.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +2*a(n-2) +2*a(n-3) -a(n-4) -2*a(n-5) -3*a(n-6) -a(n-7) +a(n-8) for n>11
EXAMPLE
Some solutions for n=5
..0..0..1. .0..1..1. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..1..1
..0..0..1. .0..1..1. .0..0..0. .0..1..0. .0..0..0. .0..1..0. .0..1..1
..0..0..0. .1..1..1. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .1..1..1
..1..0..0. .1..1..1. .0..0..0. .0..0..0. .1..0..0. .1..0..0. .0..1..1
..0..1..0. .1..1..1. .0..1..1. .0..0..0. .0..1..0. .0..1..0. .1..0..1
CROSSREFS
Cf. A305245.
Sequence in context: A367397 A062859 A300745 * A301106 A008237 A008120
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 28 2018
STATUS
approved