A300422 Number of n X 3 0..1 arrays with every element equal to 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 10, 53, 272, 1390, 7179, 37042, 191135, 986243, 5089160, 26260738, 135509178, 699246723, 3608214131, 18618905868, 96076245152, 495767309402, 2558230969852, 13200841543223, 68118250289325, 351500016661296, 1813790888521066

Offset

1,2

Comments

Column 3 of A300427.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +3*a(n-2) -11*a(n-3) +a(n-4) -11*a(n-5) -2*a(n-6) +14*a(n-7) -6*a(n-8) -8*a(n-9) -4*a(n-10) -8*a(n-11) +4*a(n-13) for n>14.

Example

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

Crossrefs

Cf. A300427.

Sequence in context: A298564 A063899 A006889 * A300684 A300607 A301349

Adjacent sequences: A300419 A300420 A300421 * A300423 A300424 A300425

Keyword

nonn

Author

R. H. Hardin, Mar 05 2018

Status

approved