A305580 Number of nXn 0..1 arrays with every element unequal to 0, 1, 2, 7 or 8 king-move adjacent elements, with upper left element zero.

1, 4, 6, 15, 76, 1897, 50618, 1944635, 206386330, 39654762470, 12122540208729, 7706375033488022, 9485494637120246765, 20755111336456755801193

Offset

1,2

Comments

Diagonal of A305586.

Links

Table of n, a(n) for n=1..14.

Example

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

Crossrefs

Cf. A305586.

Sequence in context: A294070 A073603 A064910 * A191311 A086714 A356801

Adjacent sequences: A305577 A305578 A305579 * A305581 A305582 A305583

Keyword

nonn

Author

R. H. Hardin, Jun 05 2018

Status

approved