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A262421
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Number of (2+1) X (n+1) 0..1 arrays with each row divisible by 3 and column not divisible by 3, read as a binary number with top and left being the most significant bits.
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1
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5, 4, 45, 114, 709, 2892, 15293, 72370, 367125, 1808844, 9078925, 45214674, 226307429, 1130307532, 5653140573, 28257215730, 141297157045, 706426855884, 3532211260205, 17660645718034, 88303765183749, 441515959527372
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OFFSET
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1,1
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..210
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FORMULA
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Empirical: a(n) = 5*a(n-1) + 12*a(n-2) - 60*a(n-3) - 39*a(n-4) + 195*a(n-5) + 28*a(n-6) - 140*a(n-7).
Empirical g.f.: x*(5 - 21*x - 35*x^2 + 141*x^3 + 34*x^4 - 140*x^5) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 + 2*x)*(1 - 5*x)*(1 - 7*x^2)). - Colin Barker, Dec 31 2018
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EXAMPLE
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Some solutions for n=4:
..1..1..0..0..0....0..1..1..0..0....1..1..1..1..0....1..1..0..1..1
..0..1..0..0..1....1..1..0..1..1....1..1..0..0..0....0..1..1..0..0
..1..1..1..1..0....0..1..1..0..0....1..1..0..1..1....1..1..0..0..0
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CROSSREFS
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Row 2 of A262420.
Sequence in context: A189748 A304151 A223527 * A305170 A192344 A181613
Adjacent sequences: A262418 A262419 A262420 * A262422 A262423 A262424
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Sep 22 2015
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STATUS
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approved
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