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A303802 Number of nX2 0..1 arrays with every element unequal to 0, 1, 3 or 4 king-move adjacent elements, with upper left element zero. 8
2, 5, 7, 17, 35, 61, 127, 265, 507, 1013, 2071, 4097, 8147, 16429, 32815, 65401, 131115, 262373, 523975, 1048433, 2097923, 4193821, 8387551, 16779241, 33554523, 67104725, 134221687, 268439777, 536858675, 1073745421, 2147504527, 4294939225 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A303808.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 2*a(n-1) -a(n-2) +4*a(n-3) -4*a(n-4) for n>5

EXAMPLE

Some solutions for n=5

..0..1. .0..0. .0..0. .0..1. .0..0. .0..0. .0..1. .0..0. .0..1. .0..0

..0..0. .0..0. .0..0. .1..1. .0..1. .0..1. .0..0. .0..1. .1..1. .1..0

..1..1. .0..0. .1..0. .0..0. .1..1. .1..1. .0..0. .1..1. .0..0. .1..1

..0..0. .0..0. .1..1. .1..0. .1..1. .1..1. .0..0. .1..1. .1..1. .1..1

..1..0. .0..0. .1..1. .1..1. .1..1. .1..0. .0..1. .0..1. .1..0. .1..0

CROSSREFS

Cf. A303808.

Sequence in context: A318731 A256062 A303677 * A045357 A168035 A247323

Adjacent sequences:  A303799 A303800 A303801 * A303803 A303804 A303805

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 30 2018

STATUS

approved

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Last modified May 20 05:35 EDT 2019. Contains 323418 sequences. (Running on oeis4.)