A301610 Number of nX3 0..1 arrays with every element equal to 1, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.

1, 11, 62, 367, 2131, 12467, 72758, 425003, 2481842, 14494425, 84647239, 494344466, 2886987133, 16860117364, 98463698698, 575031667957, 3358206190785, 19612048586036, 114535089777733, 668889165654501, 3906337494564368

Offset

1,2

Comments

Column 3 of A301615.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +12*a(n-2) -5*a(n-3) -14*a(n-4) +14*a(n-6) +4*a(n-7) -3*a(n-8) -5*a(n-9) +a(n-10)

Example

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

Crossrefs

Cf. A301615.

Sequence in context: A227087 A052051 A162946 * A298046 A120723 A053367

Adjacent sequences: A301607 A301608 A301609 * A301611 A301612 A301613

Keyword

nonn

Author

R. H. Hardin, Mar 24 2018

Status

approved