A303803 - OEIS

A303803

Number of nX3 0..1 arrays with every element unequal to 0, 1, 3 or 4 king-move adjacent elements, with upper left element zero.

3, 7, 9, 15, 27, 47, 83, 161, 321, 641, 1293, 2665, 5603, 11957, 25767, 55917, 122063, 267835, 590085, 1303845, 2886875, 6401619, 14212171, 31580661, 70221799, 156218863, 347655099, 773886975, 1723025065, 3836799089, 8544630497

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OFFSET

1,1

COMMENTS

Column 3 of A303808.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) -a(n-2) -3*a(n-3) +6*a(n-4) -5*a(n-5) -2*a(n-6) -a(n-7) -6*a(n-8) +4*a(n-9) +2*a(n-10)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A303808.

Sequence in context: A128539 A192118 A282534 * A304850 A306740 A320022

Adjacent sequences: A303800 A303801 A303802 * A303804 A303805 A303806

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 30 2018

STATUS

approved