A305637 Number of n X 3 0..1 arrays with every element unequal to 0, 1, 2, 4, 5 or 6 king-move adjacent elements, with upper left element zero.

4, 14, 29, 78, 255, 743, 2197, 6663, 20052, 60193, 181342, 546463, 1645639, 4957325, 14936474, 45001409, 135584151, 408514453, 1230861778, 3708615800, 11174194280, 33668360081, 101444455039, 305657427545, 920962321425, 2774910487762

Offset

1,1

Comments

Column 3 of A305642.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +3*a(n-2) +9*a(n-3) -11*a(n-4) -37*a(n-5) -56*a(n-6) +14*a(n-7) +135*a(n-8) +177*a(n-9) +40*a(n-10) -179*a(n-11) -188*a(n-12) -61*a(n-13) +34*a(n-14) +3*a(n-15) for n>17.

Example

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

Crossrefs

Cf. A305642.

Sequence in context: A338311 A244714 A218212 * A103779 A049451 A079776

Adjacent sequences: A305634 A305635 A305636 * A305638 A305639 A305640

Keyword

nonn

Author

R. H. Hardin, Jun 07 2018

Status

approved