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A296720 Number of n X 3 0..1 arrays with each 1 adjacent to 0, 2 or 4 king-move neighboring 1s. 1
5, 21, 69, 258, 963, 3493, 12860, 47305, 173498, 637397, 2341283, 8597415, 31576458, 115970574, 425911328, 1564226500, 5744847726, 21098720647, 77488048294, 284585727060, 1045180704781, 3838572624574, 14097695093525, 51775756521020 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) + 3*a(n-2) + 4*a(n-3) - 19*a(n-4) - 14*a(n-5) + 9*a(n-6) + 14*a(n-7) + 6*a(n-8) - 3*a(n-9) - 2*a(n-10).

Empirical g.f.: x*(5 + 6*x - 9*x^2 - 32*x^3 - 7*x^4 + 23*x^5 + 20*x^6 + 3*x^7 - 5*x^8 - 2*x^9) / ((1 - x)*(1 - 2*x - 5*x^2 - 9*x^3 + 10*x^4 + 24*x^5 + 15*x^6 + x^7 - 5*x^8 - 2*x^9)). - Colin Barker, Feb 24 2019

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

CROSSREFS

Column 3 of A296725.

Sequence in context: A335982 A271282 A203287 * A099899 A269566 A271492

Adjacent sequences:  A296717 A296718 A296719 * A296721 A296722 A296723

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 19 2017

STATUS

approved

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Last modified January 27 10:39 EST 2022. Contains 350607 sequences. (Running on oeis4.)