A300349 Number of n X 7 0..1 arrays with every element equal to 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

8, 223, 306, 729, 1496, 3092, 5451, 12038, 22852, 46541, 95132, 196177, 405629, 840634, 1744597, 3623639, 7531533, 15660855, 32571028, 67753153, 140956422, 293282485, 610274374, 1269978478, 2642991878, 5500729098, 11448984844

Offset

1,1

Comments

Column 7 of A300350.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -8*a(n-2) +4*a(n-3) +a(n-8) -3*a(n-9) +4*a(n-10) -2*a(n-11) +a(n-12) -a(n-13) -a(n-18) +a(n-19) for n>25.

Example

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

Crossrefs

Cf. A300350.

Sequence in context: A299734 A006919 A179122 * A300434 A300768 A300638

Adjacent sequences: A300346 A300347 A300348 * A300350 A300351 A300352

Keyword

nonn

Author

R. H. Hardin, Mar 03 2018

Status

approved