A303881 Number of n X n 0..1 arrays with every element unequal to 0, 2, 3 or 4 king-move adjacent elements, with upper left element zero.

1, 4, 11, 166, 1150, 24985, 308271, 7577931, 148783767, 4946437814, 177760275047

Offset

1,2

Comments

Diagonal of A303888.

Links

Table of n, a(n) for n=1..11.

Example

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

Crossrefs

Cf. A303888.

Sequence in context: A006248 A119571 A089920 * A305277 A118197 A092658

Adjacent sequences: A303878 A303879 A303880 * A303882 A303883 A303884

Keyword

nonn

Author

R. H. Hardin, May 02 2018

Status

approved