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A298569
Number of nX2 0..1 arrays with every element equal to 0, 2, 4, 5 or 7 king-move adjacent elements, with upper left element zero.
1
1, 4, 4, 8, 36, 52, 100, 356, 628, 1220, 3668, 7268, 14516, 38980, 82452, 169508, 423284, 926980, 1953236, 4661476, 10384180, 22302148, 51781012, 116208548, 253089012, 578128516, 1300672852, 2860550756, 6473222836, 14566091588
OFFSET
1,2
COMMENTS
Column 2 of A298575.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +8*a(n-3) -4*a(n-4)
EXAMPLE
Some solutions for n=5
..0..0. .0..1. .0..0. .0..1. .0..0. .0..0. .0..1. .0..1. .0..0. .0..0
..1..0. .1..1. .0..1. .1..1. .1..0. .0..1. .1..1. .0..0. .0..1. .0..1
..1..1. .1..1. .1..1. .0..0. .1..1. .0..0. .1..1. .0..0. .1..1. .1..1
..1..1. .1..0. .1..1. .0..1. .0..0. .1..1. .0..1. .0..0. .0..0. .1..1
..1..0. .0..0. .0..1. .0..0. .0..1. .0..1. .1..1. .1..0. .0..1. .1..0
CROSSREFS
Cf. A298575.
Sequence in context: A137717 A096252 A102369 * A281717 A205971 A118016
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 22 2018
STATUS
approved