A303676 Number of n X n 0..1 arrays with every element unequal to 0, 1 or 3 king-move adjacent elements, with upper left element zero.

1, 5, 9, 28, 76, 177, 367, 774, 1684, 3639, 7597, 15617, 32101, 66074, 135096, 274104, 553668, 1116275, 2245277, 4501938, 9000074, 17953486, 35749382, 71056212, 140977366, 279246077, 552333115, 1091040731

Offset

1,2

Comments

Diagonal of A303682.

Links

Table of n, a(n) for n=1..28.

Example

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

Crossrefs

Cf. A303682.

Sequence in context: A147367 A147230 A192914 * A163779 A280487 A191013

Adjacent sequences: A303673 A303674 A303675 * A303677 A303678 A303679

Keyword

nonn

Author

R. H. Hardin, Apr 28 2018

Status

approved