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A279460 Number of n X 2 0..1 arrays with no element equal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1
0, 2, 6, 20, 66, 210, 658, 2036, 6236, 18928, 57032, 170790, 508748, 1508462, 4454576, 13107640, 38446722, 112448726, 328044512, 954771282, 2772970950, 8038036642, 23258558892, 67190053760, 193807573324, 558249440024, 1605908314802 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) - 2*a(n-2) - 3*a(n-4) - 14*a(n-5) - 14*a(n-6) - 14*a(n-7) - 13*a(n-8) - 6*a(n-9) - a(n-10).

Empirical g.f.: 2*x^2*(1 + x)*(1 - 2*x + 2*x^2 - 3*x^3 - x^4 - x^5 - x^6) / (1 - 2*x - x^2 - 2*x^3 - 3*x^4 - x^5)^2. - Colin Barker, Feb 11 2019

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 2 of A279466.

Sequence in context: A148474 A156831 A027061 * A083323 A174846 A111285

Adjacent sequences:  A279457 A279458 A279459 * A279461 A279462 A279463

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 12 2016

STATUS

approved

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Last modified May 19 20:41 EDT 2019. Contains 323410 sequences. (Running on oeis4.)