A302158 Number of nX3 0..1 arrays with every element equal to 0, 1 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

3, 9, 7, 17, 31, 57, 111, 265, 527, 1065, 2431, 4953, 10095, 22537, 46527, 95417, 209679, 436585, 900191, 1955353, 4093999, 8480457, 18265087, 38377337, 79802575, 170819881, 359693471, 750304217, 1598909295, 3371088777, 7049660735

Offset

1,1

Comments

Column 3 of A302163.

Links

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

Formula

Empirical: a(n) = a(n-1) +8*a(n-3) -6*a(n-4) -4*a(n-6) +4*a(n-7) for n>11

Example

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

Crossrefs

Cf. A302163.

Sequence in context: A214661 A178414 A220654 * A337974 A137299 A329238

Adjacent sequences: A302155 A302156 A302157 * A302159 A302160 A302161

Keyword

nonn

Author

R. H. Hardin, Apr 02 2018

Status

approved