A305247 Number of n X 3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 8 king-move adjacent elements, with upper left element zero.

3, 7, 10, 17, 34, 65, 121, 244, 502, 1023, 2112, 4430, 9384, 20081, 43341, 94137, 205643, 451538, 995569, 2202392, 4885309, 10860185, 24185234, 53936572, 120423583, 269112504, 601825056, 1346656482, 3014688479, 6751281413

Offset

1,1

Comments

Column 3 of A305252.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +a(n-2) +a(n-4) -4*a(n-5) -a(n-6) -10*a(n-7) -10*a(n-8) -3*a(n-9) +6*a(n-11) +2*a(n-12).

Example

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

Crossrefs

Cf. A305252.

Sequence in context: A022120 A041191 A304216 * A316547 A041251 A042435

Adjacent sequences: A305244 A305245 A305246 * A305248 A305249 A305250

Keyword

nonn

Author

R. H. Hardin, May 28 2018

Status

approved