A305906 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 4, 5 or 7 king-move adjacent elements, with upper left element zero.

4, 14, 35, 98, 358, 1124, 3534, 11667, 37816, 121881, 396149, 1286340, 4168472, 13525005, 43893856, 142389105, 461961170, 1498926869, 4863215164, 15778543522, 51194303437, 166101128424, 538917021528, 1748530951647, 5673154219369

Offset

1,1

Comments

Column 3 of A305911.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +4*a(n-2) +11*a(n-3) -19*a(n-4) -49*a(n-5) -54*a(n-6) +80*a(n-7) +161*a(n-8) +107*a(n-9) -128*a(n-10) -154*a(n-11) -22*a(n-12) +37*a(n-13) -26*a(n-14) -33*a(n-15) for n>16

Example

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

Crossrefs

Cf. A305911.

Sequence in context: A307260 A288678 A295180 * A177110 A213045 A061989

Adjacent sequences: A305903 A305904 A305905 * A305907 A305908 A305909

Keyword

nonn

Author

R. H. Hardin, Jun 14 2018

Status

approved