A305679 Number of nXn 0..1 arrays with every element unequal to 0, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.

1, 4, 25, 1595, 383910, 351440611, 1172824606532, 14227138873003015, 624906012671792336577

Offset

1,2

Comments

Diagonal of A305685.

Links

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

Example

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

Crossrefs

Cf. A305685.

Sequence in context: A072882 A014253 A132553 * A317061 A144229 A316926

Adjacent sequences: A305676 A305677 A305678 * A305680 A305681 A305682

Keyword

nonn

Author

R. H. Hardin, Jun 08 2018

Status

approved