A304850 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 7 king-move adjacent elements, with upper left element zero.

3, 7, 9, 15, 29, 51, 91, 177, 363, 739, 1513, 3143, 6655, 14303, 31045, 67793, 148749, 327891, 725675, 1610855, 3583125, 7981893, 17801055, 39736009, 88762991, 198384777, 443558549, 992011343, 2219095455, 4964860519, 11109443475

Offset

1,1

Comments

Column 3 of A304855.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -6*a(n-3) +7*a(n-4) -a(n-5) -10*a(n-6) +4*a(n-7) -4*a(n-8) +3*a(n-9) +13*a(n-10) -5*a(n-11) -3*a(n-12)

Example

Some solutions for n=5
..0..0..1. .0..1..1. .0..0..0. .0..1..1. .0..1..1. .0..0..1. .0..1..1
..0..0..0. .1..1..1. .1..0..0. .0..0..1. .1..1..1. .0..0..0. .1..1..1
..0..1..1. .1..1..1. .1..0..1. .0..0..0. .1..1..1. .0..0..0. .1..1..1
..0..0..0. .1..1..1. .0..0..1. .0..0..0. .1..1..0. .0..0..0. .1..1..1
..0..0..1. .1..1..1. .0..0..0. .1..0..0. .1..0..0. .1..0..0. .1..1..0

Crossrefs

Cf. A304855.

Sequence in context: A192118 A282534 A303803 * A306740 A320022 A057463

Adjacent sequences: A304847 A304848 A304849 * A304851 A304852 A304853

Keyword

nonn

Author

R. H. Hardin, May 19 2018

Status

approved