A301880 Number of nX4 0..1 arrays with every element equal to 0, 1 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

5, 18, 58, 203, 673, 2340, 7883, 27175, 92411, 316916, 1082302, 3703582, 12666854, 43318597, 148204170, 506815629, 1733886818, 5929952262, 20285442903, 69382426261, 237332736304, 811785135443, 2776754678163, 9497916687371

Offset

1,1

Comments

Column 4 of A301884.

Links

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

Formula

Empirical: a(n) = a(n-1) +12*a(n-2) -2*a(n-3) -38*a(n-4) +a(n-5) +12*a(n-6) -a(n-8)

Example

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

Crossrefs

Cf. A301884.

Sequence in context: A335551 A235612 A000340 * A034567 A133648 A284968

Adjacent sequences: A301877 A301878 A301879 * A301881 A301882 A301883

Keyword

nonn

Author

R. H. Hardin, Mar 28 2018

Status

approved