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A305247
Number of n X 3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 8 king-move adjacent elements, with upper left element zero.
1
3, 7, 10, 17, 34, 65, 121, 244, 502, 1023, 2112, 4430, 9384, 20081, 43341, 94137, 205643, 451538, 995569, 2202392, 4885309, 10860185, 24185234, 53936572, 120423583, 269112504, 601825056, 1346656482, 3014688479, 6751281413
OFFSET
1,1
COMMENTS
Column 3 of A305252.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +a(n-2) +a(n-4) -4*a(n-5) -a(n-6) -10*a(n-7) -10*a(n-8) -3*a(n-9) +6*a(n-11) +2*a(n-12).
EXAMPLE
Some solutions for n=5:
..0..0..0. .0..1..1. .0..1..1. .0..0..1. .0..0..0. .0..1..1. .0..1..1
..0..0..0. .1..1..1. .1..1..1. .0..0..0. .0..0..1. .1..1..1. .0..0..1
..0..0..0. .1..1..1. .1..1..1. .0..0..0. .0..1..1. .1..1..1. .0..0..0
..0..1..0. .0..1..1. .1..1..1. .0..0..0. .1..1..1. .1..1..0. .0..0..0
..0..0..0. .0..0..1. .0..1..1. .0..0..0. .1..1..1. .1..0..0. .0..0..0
CROSSREFS
Cf. A305252.
Sequence in context: A022120 A041191 A304216 * A316547 A041251 A042435
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 28 2018
STATUS
approved