A298128 Number of nX3 0..1 arrays with every element equal to 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.

0, 2, 4, 13, 62, 223, 826, 3200, 12098, 45921, 174562, 662609, 2516820, 9558976, 36301634, 137870761, 523613086, 1988599181, 7552421216, 28682975530, 108933718764, 413714339533, 1571226249932, 5967286725891, 22662879439242

Offset

1,2

Comments

Column 3 of A298133.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +4*a(n-2) -12*a(n-4) -7*a(n-5) -2*a(n-6) -13*a(n-7) +46*a(n-8) +28*a(n-9) -78*a(n-10) -23*a(n-11) +61*a(n-12) +14*a(n-13) -8*a(n-14) -2*a(n-15) -14*a(n-16) +4*a(n-18)

Example

Some solutions for n=7
..0..1..1. .0..1..1. .0..0..1. .0..0..1. .0..0..0. .0..0..1. .0..0..1
..0..0..1. .0..0..1. .0..1..1. .0..1..1. .1..0..1. .0..1..1. .0..1..1
..0..0..1. .1..1..0. .0..1..0. .1..0..0. .1..1..1. .0..1..0. .1..0..1
..0..1..1. .1..0..0. .0..0..0. .1..1..0. .1..1..1. .1..0..0. .1..0..0
..0..1..1. .0..1..1. .1..1..1. .1..1..0. .1..0..1. .1..1..1. .0..1..1
..0..1..0. .0..1..1. .0..1..0. .0..1..0. .1..0..0. .0..0..1. .0..1..0
..0..0..0. .0..0..1. .0..0..0. .0..0..0. .1..1..0. .0..1..1. .0..0..0

Crossrefs

Cf. A298133.

Sequence in context: A020097 A139149 A297861 * A132786 A298065 A298714

Adjacent sequences: A298125 A298126 A298127 * A298129 A298130 A298131

Keyword

nonn

Author

R. H. Hardin, Jan 13 2018

Status

approved