A301947 Number of nX4 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

2, 16, 123, 947, 7326, 56710, 439078, 3399722, 26323903, 203825456, 1578217598, 12220118582, 94620225492, 732643232114, 5672847473255, 43924787764759, 340109088005893, 2633460459021237, 20390851741033347, 157886112662767667

Offset

1,1

Comments

Column 4 of A301951.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -8*a(n-2) -14*a(n-3) +4*a(n-4) +4*a(n-5) -a(n-6)

Example

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

Crossrefs

Cf. A301951.

Sequence in context: A209361 A341925 A229808 * A027309 A241466 A069868

Adjacent sequences: A301944 A301945 A301946 * A301948 A301949 A301950

Keyword

nonn

Author

R. H. Hardin, Mar 29 2018

Status

approved