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A301603 Number of nX3 0..1 arrays with every element equal to 0, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero. 1
1, 2, 2, 8, 13, 26, 55, 154, 356, 884, 2161, 5440, 13511, 33780, 84398, 211338, 528999, 1325014, 3319005, 8315948, 20836784, 52214530, 130847203, 327910100, 821772985, 2059471558, 5161348174, 12935209836, 32417941793, 81245379630, 203616360639 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A301608.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +3*a(n-2) +4*a(n-3) +2*a(n-4) -8*a(n-5) -17*a(n-6) -19*a(n-7) -9*a(n-8) +6*a(n-9) +21*a(n-10) +15*a(n-11) +11*a(n-12) -2*a(n-13) -2*a(n-14) -4*a(n-15) -a(n-16) -a(n-17) +a(n-18)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A301608.

Sequence in context: A006663 A094941 A002785 * A292038 A045686 A045677

Adjacent sequences:  A301600 A301601 A301602 * A301604 A301605 A301606

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 24 2018

STATUS

approved

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Last modified June 25 12:01 EDT 2019. Contains 324352 sequences. (Running on oeis4.)