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A305091
Number of n X 2 0..1 arrays with every element unequal to 1, 2, 4, 6 or 7 king-move adjacent elements, with upper left element zero.
2
1, 3, 9, 10, 27, 109, 168, 349, 1229, 2490, 4767, 14401, 33504, 66377, 175249, 433386, 909235, 2208549, 5522840, 12201285, 28458341, 70294586, 161026423, 370622297, 898784848, 2102285073, 4841334921, 11557476010, 27287134763, 63194732573
OFFSET
1,2
COMMENTS
Column 2 of A305097.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +8*a(n-3) -16*a(n-5) for n>6.
EXAMPLE
Some solutions for n=5
..0..1. .0..0. .0..1. .0..1. .0..1. .0..1. .0..1. .0..1. .0..1. .0..1
..1..0. .1..1. .1..0. .0..1. .1..0. .0..1. .0..1. .0..1. .0..1. .1..0
..0..0. .1..1. .1..1. .1..1. .0..0. .1..1. .0..0. .0..0. .0..0. .0..0
..1..0. .1..0. .1..0. .0..1. .0..0. .1..0. .0..1. .1..0. .0..1. .0..1
..0..1. .0..1. .0..1. .0..1. .1..1. .0..1. .0..1. .0..1. .1..0. .0..1
CROSSREFS
Cf. A305097.
Sequence in context: A060140 A340387 A025616 * A282635 A308084 A136852
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 25 2018
STATUS
approved