A305091 Number of n X 2 0..1 arrays with every element unequal to 1, 2, 4, 6 or 7 king-move adjacent elements, with upper left element zero.

1, 3, 9, 10, 27, 109, 168, 349, 1229, 2490, 4767, 14401, 33504, 66377, 175249, 433386, 909235, 2208549, 5522840, 12201285, 28458341, 70294586, 161026423, 370622297, 898784848, 2102285073, 4841334921, 11557476010, 27287134763, 63194732573

Offset

1,2

Comments

Column 2 of A305097.

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +8*a(n-3) -16*a(n-5) for n>6.

Example

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

Crossrefs

Cf. A305097.

Sequence in context: A060140 A340387 A025616 * A282635 A308084 A136852

Adjacent sequences: A305088 A305089 A305090 * A305092 A305093 A305094

Keyword

nonn

Author

R. H. Hardin, May 25 2018

Status

approved