A302665 Number of nX3 0..1 arrays with every element equal to 1, 2, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

1, 14, 43, 194, 691, 2802, 10660, 41839, 161878, 630842, 2449576, 9528949, 37035686, 144004769, 559817133, 2176500315, 8461548011, 32896646099, 127893433256, 497218644961, 1933060065053, 7515258095114, 29217439753668, 113590121120145

Offset

1,2

Comments

Column 3 of A302670.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +4*a(n-2) -11*a(n-3) -27*a(n-4) -12*a(n-5) +85*a(n-6) +22*a(n-7) -22*a(n-8) -108*a(n-9) +72*a(n-10) -80*a(n-11) +120*a(n-12) +64*a(n-14)

Example

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

Crossrefs

Cf. A302670.

Sequence in context: A120714 A041378 A302219 * A041380 A151990 A156166

Adjacent sequences: A302662 A302663 A302664 * A302666 A302667 A302668

Keyword

nonn

Author

R. H. Hardin, Apr 11 2018

Status

approved