A302376 Number of nX3 0..1 arrays with every element equal to 1, 2, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

1, 15, 76, 475, 2771, 16451, 97160, 574671, 3397622, 20089993, 118787443, 702368950, 4152971123, 24555730380, 145193342488, 858500551625, 5076149984859, 30014306641852, 177468870003729, 1049339576968817

Offset

1,2

Comments

Column 3 of A302381.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +13*a(n-2) -5*a(n-3) -28*a(n-4) -11*a(n-5) +11*a(n-6) +4*a(n-7) +6*a(n-8) +24*a(n-9) +16*a(n-10) -32*a(n-11)

Example

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

Crossrefs

Cf. A302381.

Sequence in context: A212093 A212241 A000477 * A041430 A156941 A205440

Adjacent sequences: A302373 A302374 A302375 * A302377 A302378 A302379

Keyword

nonn

Author

R. H. Hardin, Apr 06 2018

Status

approved