A304888 Number of n X n 0..1 arrays with every element unequal to 0, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.

1, 4, 11, 246, 3145, 123297, 7309444, 527157688, 106200560327, 22393951865040

Offset

1,2

Comments

Diagonal of A304894.

Links

Table of n, a(n) for n=1..10.

Example

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

Crossrefs

Cf. A304894.

Sequence in context: A305277 A118197 A092658 * A316572 A216571 A299046

Adjacent sequences: A304885 A304886 A304887 * A304889 A304890 A304891

Keyword

nonn

Author

R. H. Hardin, May 20 2018

Status

approved