A297818 - OEIS

A297818

Number of nX3 0..1 arrays with every element equal to 1, 2 or 3 king-move adjacent elements, with upper left element zero.

1, 17, 48, 146, 399, 1114, 3124, 8861, 25130, 71196, 201467, 570100, 1613454, 4566805, 12926144, 36586306, 103553095, 293094410, 829569532, 2348002541, 6645755138, 18810052924, 53239705819, 150688904948, 426507740022

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OFFSET

1,2

COMMENTS

Column 3 of A297823.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) -a(n-2) -a(n-3) +7*a(n-4) -a(n-5) +2*a(n-6) +2*a(n-7) +2*a(n-9) for n>11

EXAMPLE

Some solutions for n=7

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

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

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

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

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

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

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

CROSSREFS

Cf. A297823.

Sequence in context: A159850 A031122 A051869 * A297988 A210372 A239130

Adjacent sequences: A297815 A297816 A297817 * A297819 A297820 A297821

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 06 2018

STATUS

approved