

A279897


Number of n X 3 0..2 arrays with no element unequal to a strict majority of its kingmove neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.


1



2, 6, 9, 20, 43, 94, 213, 456, 1003, 2146, 4625, 9852, 20983, 44438, 93917, 197808, 415683, 871370, 1822889, 3805924, 7932303, 16505342, 34292341, 71147800, 147422043, 305096754, 630699073, 1302409036, 2686840103, 5537724006
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OFFSET

1,1


LINKS



FORMULA

Empirical: a(n) = 2*a(n1) + 3*a(n2)  4*a(n3)  4*a(n4) for n>7.
G.f.: x*(2 + 2*x  9*x^2  8*x^3 + 8*x^4 + 8*x^5 + 12*x^6) / ((1 + x)^2*(1  2*x)^2).
a(n) = (1280*(1)^n + 31*2^(2+n)  264*(1)^n*n + 33*2^n*n) / 216 for n>3.
(End)


EXAMPLE

Some solutions for n=4:
..0..0..0. .0..1..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0
..1..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .1..0..0. .0..0..0
..1..1..1. .0..0..0. .1..0..0. .0..0..0. .0..1..0. .2..2..2. .0..0..0
..1..1..1. .0..0..0. .0..0..0. .1..0..0. .0..0..0. .2..2..2. .0..0..1


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



