A305636 Number of nXn 0..1 arrays with every element unequal to 0, 1, 2, 4, 5 or 6 king-move adjacent elements, with upper left element zero.

1, 4, 29, 334, 8734, 385282, 42274045, 12972861669, 10445509134407

Offset

1,2

Comments

Diagonal of A305642.

Links

Table of n, a(n) for n=1..9.

Example

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

Crossrefs

Cf. A305642.

Sequence in context: A118795 A325478 A099700 * A276728 A256006 A137646

Adjacent sequences: A305633 A305634 A305635 * A305637 A305638 A305639

Keyword

nonn

Author

R. H. Hardin, Jun 07 2018

Status

approved