A281760 - OEIS

A281760

Number of n X 3 0..1 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

2, 14, 47, 90, 201, 374, 672, 1172, 2015, 3442, 5859, 9952, 16876, 28574, 48309, 81554, 137477, 231418, 389016, 653080, 1095019, 1833842, 3067719, 5126372, 8557988, 14273314, 23784417, 39600082, 65880265, 109518782, 181933584, 302025692

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OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>11.

Empirical g.f.: x*(2 + 6*x - x^2 - 38*x^3 + 49*x^4 - 32*x^5 - 26*x^6 + 36*x^7 + 6*x^8 + 8*x^9 + 8*x^10) / ((1 - x)^2*(1 - x - x^2)^2). - Colin Barker, Feb 20 2019

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 3 of A281765.

Sequence in context: A036659 A079937 A324915 * A197885 A200193 A188571

Adjacent sequences: A281757 A281758 A281759 * A281761 A281762 A281763

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 29 2017

STATUS

approved