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A305218 Number of nX3 0..1 arrays with every element unequal to 2, 3, 5, 6 or 7 king-move adjacent elements, with upper left element zero. 2
0, 4, 8, 15, 31, 92, 264, 784, 2378, 7342, 22596, 69617, 214983, 664217, 2052307, 6342935, 19606074, 60603932, 187335711, 579091828, 1790098137, 5533594957, 17105617402, 52877461311, 163456660240, 505283076436, 1561949355656 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A305223.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +5*a(n-2) -12*a(n-4) -15*a(n-5) +3*a(n-6) +30*a(n-7) +14*a(n-8) -40*a(n-9) -44*a(n-10) +23*a(n-11) +66*a(n-12) +22*a(n-13) -15*a(n-14) -6*a(n-15) for n>18

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A305223.

Sequence in context: A027961 A301203 A018921 * A321500 A103536 A011970

Adjacent sequences:  A305215 A305216 A305217 * A305219 A305220 A305221

KEYWORD

nonn

AUTHOR

R. H. Hardin, May 27 2018

STATUS

approved

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Last modified February 27 15:59 EST 2020. Contains 332307 sequences. (Running on oeis4.)