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A303803 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3 or 4 king-move adjacent elements, with upper left element zero. 1
3, 7, 9, 15, 27, 47, 83, 161, 321, 641, 1293, 2665, 5603, 11957, 25767, 55917, 122063, 267835, 590085, 1303845, 2886875, 6401619, 14212171, 31580661, 70221799, 156218863, 347655099, 773886975, 1723025065, 3836799089, 8544630497 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 3 of A303808.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) -a(n-2) -3*a(n-3) +6*a(n-4) -5*a(n-5) -2*a(n-6) -a(n-7) -6*a(n-8) +4*a(n-9) +2*a(n-10)
EXAMPLE
Some solutions for n=5
..0..0..1. .0..0..1. .0..1..1. .0..0..0. .0..0..0. .0..0..0. .0..0..1
..0..0..0. .0..1..1. .1..1..1. .0..0..0. .0..0..0. .0..0..0. .0..0..0
..0..0..0. .1..1..1. .1..1..1. .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..0..1. .0..0..0
..0..1..1. .0..1..1. .0..0..1. .0..0..0. .0..0..1. .0..1..1. .1..0..0
CROSSREFS
Cf. A303808.
Sequence in context: A128539 A192118 A282534 * A304850 A306740 A320022
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 30 2018
STATUS
approved

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Last modified March 28 22:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)