A302382 Number of 3Xn 0..1 arrays with every element equal to 1, 2, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

0, 11, 76, 430, 2886, 19215, 127535, 847604, 5631313, 37416247, 248600404, 1651756796, 10974620983, 72917744789, 484481101148, 3218996316583, 21387701319096, 142104471542165, 944172564092345, 6273284870138765

Offset

1,2

Comments

Row 3 of A302381.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +15*a(n-2) +14*a(n-3) +19*a(n-4) +8*a(n-5) +9*a(n-6) -9*a(n-7) +4*a(n-8) -5*a(n-9) +3*a(n-10) -3*a(n-11) -5*a(n-12) +a(n-13) -2*a(n-14) for n>15

Example

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

Crossrefs

Cf. A302381.

Sequence in context: A055901 A036427 A122589 * A034269 A256597 A245561

Adjacent sequences: A302379 A302380 A302381 * A302383 A302384 A302385

Keyword

nonn

Author

R. H. Hardin, Apr 06 2018

Status

approved