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A297870
Number of nX2 0..1 arrays with every element equal to 2, 3 or 5 king-move adjacent elements, with upper left element zero.
9
0, 1, 3, 2, 11, 13, 34, 65, 123, 266, 499, 1037, 2042, 4089, 8219, 16338, 32827, 65485, 131090, 262193, 524155, 1048794, 2096899, 4194509, 8388586, 16776937, 33555099, 67107874, 134218827, 268434701, 536870786, 1073743393, 2147480443, 4294971818
OFFSET
1,3
COMMENTS
Column 2 of A297876.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +3*a(n-2) -4*a(n-4)
EXAMPLE
Some solutions for n=7
..0..0. .0..0. .0..0. .0..0. .0..0. .0..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. .1..0. .1..0
..0..0. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1
..0..0. .1..1. .1..0. .1..1. .1..0. .1..0. .1..1. .0..0. .0..1. .0..0
..0..0. .1..1. .0..0. .0..0. .0..0. .0..0. .1..1. .0..0. .0..0. .0..0
..1..1. .1..1. .1..0. .0..1. .0..1. .1..1. .0..0. .0..0. .1..0. .1..1
..1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .0..0. .0..0. .1..1. .1..1
CROSSREFS
Cf. A297876.
Sequence in context: A134426 A122672 A194608 * A052973 A087956 A116391
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 07 2018
STATUS
approved