A306137 Number of nXn 0..1 arrays with every element unequal to 1, 2, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero.

0, 7, 90, 4691, 601535, 173607551, 138192505287, 289978184070220, 1508303074324756219

Offset

1,2

Comments

Diagonal of A306143.

Links

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

Example

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

Crossrefs

Cf. A306143.

Sequence in context: A321164 A243699 A007820 * A226624 A266236 A123694

Adjacent sequences: A306134 A306135 A306136 * A306138 A306139 A306140

Keyword

nonn

Author

R. H. Hardin, Jun 22 2018

Status

approved