A305447 - OEIS

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A305447

Number of nX3 0..1 arrays with every element unequal to 1, 2, 4, 5 or 8 king-move adjacent elements, with upper left element zero.

1, 11, 7, 20, 44, 77, 181, 379, 849, 1799, 4154, 9242, 20384, 46987, 105477, 238364, 544013, 1234035, 2805803, 6392808, 14558529, 33157368, 75581441, 172296118, 392727236, 895513084, 2042029380, 4656342833, 10619040244, 24217647660

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OFFSET

1,2

COMMENTS

Column 3 of A305452.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +3*a(n-2) +7*a(n-3) -6*a(n-4) -18*a(n-5) -26*a(n-6) +8*a(n-7) +27*a(n-8) +47*a(n-9) +16*a(n-10) -5*a(n-11) -3*a(n-12) -7*a(n-13) -20*a(n-14) -24*a(n-15) -5*a(n-16) -6*a(n-17) for n>18

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A305452.

Sequence in context: A187866 A206419 A250032 * A060954 A350214 A038321

Adjacent sequences: A305444 A305445 A305446 * A305448 A305449 A305450

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 01 2018

STATUS

approved