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A304599
Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 5 or 6 king-move adjacent elements, with upper left element zero.
1
4, 5, 13, 23, 53, 131, 330, 793, 1930, 4765, 11686, 28627, 70237, 172374, 422930, 1037573, 2545757, 6246392, 15325889, 37602947, 92261907, 226372036, 555420895, 1362767425, 3343655704, 8203918429, 20128946224, 49387923264, 121177087505
OFFSET
1,1
COMMENTS
Column 3 of A304604.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +2*a(n-2) +4*a(n-3) +2*a(n-4) -2*a(n-5) -7*a(n-6) -6*a(n-7) for n>10
EXAMPLE
Some solutions for n=5
..0..1..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..1..0
..0..0..0. .0..1..0. .0..0..0. .0..0..0. .1..0..0. .1..0..0. .0..0..0
..0..0..1. .1..0..1. .0..0..0. .0..0..1. .0..0..0. .0..0..1. .1..0..0
..0..0..0. .1..1..1. .1..0..0. .0..0..0. .0..0..1. .0..0..0. .0..0..1
..0..1..0. .1..1..1. .0..0..0. .0..1..0. .0..0..0. .0..0..0. .0..0..0
CROSSREFS
Cf. A304604.
Sequence in context: A147001 A247325 A140683 * A071341 A272898 A102981
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 15 2018
STATUS
approved