A281393 Number of n X n 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

0, 0, 131, 1020, 5892, 23216, 84474, 285076, 886900, 2652496, 7689224, 21516104, 58884471

Offset

1,3

Comments

Diagonal of A281400.

Links

Table of n, a(n) for n=1..13.

Example

Some solutions for n=4
..0..0..0..1. .0..0..1..1. .0..0..1..0. .0..1..0..0. .0..1..1..0
..1..0..1..1. .1..1..0..0. .0..1..1..1. .1..1..1..0. .1..0..0..1
..1..0..1..0. .0..1..0..1. .0..1..0..0. .0..0..1..0. .0..1..0..1
..0..1..0..0. .0..0..0..1. .0..1..0..1. .0..1..1..0. .0..1..0..0

Crossrefs

Cf. A281400.

Sequence in context: A142205 A142807 A103834 * A169645 A221154 A144247

Adjacent sequences: A281390 A281391 A281392 * A281394 A281395 A281396

Keyword

nonn

Author

R. H. Hardin, Jan 21 2017

Status

approved