A296034 - OEIS

A296034

Number of n X 3 0..1 arrays with each 1 adjacent to 2 or 4 king-move neighboring 1s.

1, 11, 31, 70, 251, 799, 2266, 7005, 21780, 65489, 199273, 610585, 1857468, 5653794, 17249124, 52563162, 160123076, 488054813, 1487412562, 4532419434, 13812563405, 42094180094, 128277984857, 390920465658, 1191319783180, 3630484158342

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OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + a(n-2) + 11*a(n-3) - 7*a(n-4) - 12*a(n-5) - 23*a(n-6) + 19*a(n-8) + 9*a(n-9) - 3*a(n-10) - 2*a(n-11).

Empirical g.f.: x*(1 + 9*x + 8*x^2 - 14*x^3 - 34*x^4 - 25*x^5 + 19*x^6 + 28*x^7 + 6*x^8 - 5*x^9 - 2*x^10) / (1 - 2*x - x^2 - 11*x^3 + 7*x^4 + 12*x^5 + 23*x^6 - 19*x^8 - 9*x^9 + 3*x^10 + 2*x^11). - Colin Barker, Feb 22 2019

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

CROSSREFS

Column 3 of A296039.

Sequence in context: A090562 A174244 A136061 * A090233 A139836 A085715

Adjacent sequences: A296031 A296032 A296033 * A296035 A296036 A296037

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 03 2017

STATUS

approved