A320367 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

8, 128, 1612, 19840, 245060, 3027408, 37398884, 462004160, 5707334644, 70505149536, 870980328164, 10759593299088, 132917867720276, 1641991390503824, 20284223429413892, 250579706152958368

Offset

1,1

Comments

Column 4 of A320371.

Links

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

Formula

Empirical: a(n) = 16*a(n-1) -50*a(n-2) +68*a(n-3) -85*a(n-4) +12*a(n-5) -36*a(n-6) -12*a(n-7) +12*a(n-8) +16*a(n-9)

Example

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

Crossrefs

Cf. A320371.

Sequence in context: A299736 A133680 A316811 * A317561 A302737 A299657

Adjacent sequences: A320364 A320365 A320366 * A320368 A320369 A320370

Keyword

nonn

Author

R. H. Hardin, Oct 11 2018

Status

approved