A305042 Number of nX3 0..1 arrays with every element unequal to 0, 2, 3, 6 or 7 king-move adjacent elements, with upper left element zero.

1, 7, 5, 9, 15, 17, 40, 73, 87, 219, 433, 583, 1421, 2954, 4560, 10528, 22379, 38588, 85235, 181931, 338249, 726130, 1543719, 3007403, 6351135, 13421225, 26878019, 56264157, 118252672, 240605844, 501399260, 1049453261, 2154572654, 4480060581

Offset

1,2

Comments

Column 3 of A305047.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +a(n-2) +5*a(n-3) -13*a(n-4) -8*a(n-5) +2*a(n-6) +19*a(n-7) +9*a(n-8) -4*a(n-9) -8*a(n-10) -4*a(n-11) for n>13

Example

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

Crossrefs

Cf. A305047.

Sequence in context: A323669 A356526 A304136 * A247870 A367689 A141391

Adjacent sequences: A305039 A305040 A305041 * A305043 A305044 A305045

Keyword

nonn

Author

R. H. Hardin, May 24 2018

Status

approved