A303793 Number of n X n 0..1 arrays with every element unequal to 0, 1, 2 or 4 king-move adjacent elements, with upper left element zero.

1, 4, 17, 90, 562, 5282, 15478, 394667, 587035, 47608207, 23125171, 8706714125, 1066431672, 2470846969189, 56568350211, 1133933765289063, 3650604967363

Offset

1,2

Comments

Diagonal of A303800.

Links

Table of n, a(n) for n=1..17.

Example

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

Crossrefs

Cf. A303800.

Sequence in context: A350474 A058279 A143405 * A141154 A347340 A355295

Adjacent sequences: A303790 A303791 A303792 * A303794 A303795 A303796

Keyword

nonn

Author

R. H. Hardin, Apr 30 2018

Status

approved