A302416 Number of 3Xn 0..1 arrays with every element equal to 0, 1, 2 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 25, 30, 66, 142, 289, 599, 1268, 2660, 5558, 11659, 24470, 51293, 107533, 225522, 472918, 991618, 2079349, 4360310, 9143205, 19172527, 40203428, 84303632, 176778210, 370690543, 777310342, 1629961137, 3417905349, 7167090042

Offset

1,1

Comments

Row 3 of A302415.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -3*a(n-2) +4*a(n-3) -4*a(n-4) +a(n-5) for n>9

Example

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

Crossrefs

Cf. A302415.

Sequence in context: A020221 A042889 A042177 * A303183 A175052 A370575

Adjacent sequences: A302413 A302414 A302415 * A302417 A302418 A302419

Keyword

nonn

Author

R. H. Hardin, Apr 07 2018

Status

approved