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A298141 Number of n X 3 0..1 arrays with every element equal to 2, 3, 6 or 7 king-move adjacent elements, with upper left element zero. 2
0, 2, 0, 2, 1, 6, 8, 15, 22, 44, 82, 152, 267, 486, 898, 1675, 3088, 5686, 10512, 19530, 36309, 67442, 125268, 232951, 433598, 807304, 1503082, 2798968, 5213647, 9713698, 18099774, 33727651, 62853728, 117142090, 218334832, 406958706, 758560313 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A298146.

LINKS

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

FORMULA

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

Empirical g.f.: x^2*(1 - x)*(2 - 2*x^2 - 3*x^3 - 2*x^4 - 6*x^5 - 3*x^6) / ((1 + x)*(1 - 2*x - 2*x^5 + 6*x^6 + 2*x^7 - x^8)). - Colin Barker, Mar 22 2018

EXAMPLE

Some solutions for n=7:

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

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

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

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

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

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

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

CROSSREFS

Cf. A298146.

Sequence in context: A116900 A254372 A196517 * A160210 A174610 A028928

Adjacent sequences:  A298138 A298139 A298140 * A298142 A298143 A298144

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 13 2018

STATUS

approved

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Last modified August 24 03:51 EDT 2019. Contains 326260 sequences. (Running on oeis4.)