A302362 Number of nX3 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

1, 12, 31, 109, 397, 1430, 5110, 18395, 66203, 238103, 856413, 3081033, 11083994, 39873749, 143444250, 516038048, 1856433397, 6678469130, 24025629692, 86431623758, 310935653685, 1118583441105, 4024076800534, 14476518656548

Offset

1,2

Comments

Column 3 of A302367.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -3*a(n-2) +9*a(n-3) -9*a(n-4) -11*a(n-5) +a(n-6) -18*a(n-7) +16*a(n-8) -12*a(n-9) -4*a(n-10) +4*a(n-11) +8*a(n-12)

Example

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

Crossrefs

Cf. A302367.

Sequence in context: A279821 A008841 A038624 * A262239 A074299 A118528

Adjacent sequences: A302359 A302360 A302361 * A302363 A302364 A302365

Keyword

nonn

Author

R. H. Hardin, Apr 06 2018

Status

approved