A304413 Number of n X n 0..1 arrays with every element unequal to 0, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero.

1, 4, 23, 835, 98568, 32181958, 29251894460, 71613287309909, 478060061219665260

Offset

1,2

Comments

Diagonal of A304419.

Links

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

Example

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

Crossrefs

Cf. A304419.

Sequence in context: A266919 A219464 A107765 * A316240 A305948 A317211

Adjacent sequences: A304410 A304411 A304412 * A304414 A304415 A304416

Keyword

nonn

Author

R. H. Hardin, May 12 2018

Status

approved