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A298959
Number of nX4 0..1 arrays with every element equal to 3, 5, 6, 7 or 8 king-move adjacent elements, with upper left element zero.
1
0, 2, 2, 7, 14, 34, 75, 174, 396, 907, 2070, 4734, 10819, 24730, 56520, 129187, 295274, 674890, 1542547, 3525702, 8058468, 18418715, 42098446, 96221670, 219927587, 502674114, 1148929360, 2626032755, 6002151458, 13718725330, 31355993907
OFFSET
1,2
COMMENTS
Column 4 of A298963.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +a(n-3) +2*a(n-4) -2*a(n-5)
EXAMPLE
Some solutions for n=5
..0..0..0..0. .0..0..0..0. .0..0..1..1. .0..0..0..0. .0..0..1..1
..0..0..0..0. .0..0..0..0. .0..0..1..1. .0..0..0..0. .0..0..1..1
..1..1..1..1. .0..0..0..0. .0..0..1..1. .1..1..0..0. .0..0..1..1
..1..1..1..1. .1..1..1..1. .1..1..1..1. .1..1..0..0. .0..0..1..1
..1..1..1..1. .1..1..1..1. .1..1..1..1. .1..1..0..0. .0..0..1..1
CROSSREFS
Cf. A298963.
Sequence in context: A156435 A344048 A228432 * A162460 A187306 A061274
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 30 2018
STATUS
approved