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A297972 Number of n X 2 0..1 arrays with every element equal to 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero. 8
0, 1, 3, 6, 17, 41, 104, 261, 655, 1646, 4133, 10381, 26072, 65481, 164459, 413046, 1037385, 2605441, 6543688, 16434781, 41276727, 103668446, 260368189, 653926981, 1642368440, 4124885761, 10359845043, 26019239206, 65348545857, 164125953561 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Column 2 of A297978.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + 3*a(n-2) + 2*a(n-3).

Empirical g.f.: x^2*(1 + 2*x) / (1 - x - 3*x^2 - 2*x^3). - Colin Barker, Feb 19 2018

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

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

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

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

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

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

CROSSREFS

Cf. A297978.

Sequence in context: A151503 A319789 A007718 * A275057 A320807 A089264

Adjacent sequences:  A297969 A297970 A297971 * A297973 A297974 A297975

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 10 2018

STATUS

approved

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Last modified July 28 00:54 EDT 2021. Contains 346316 sequences. (Running on oeis4.)