A280597 Number of n X n 0..1 arrays with no element equal to more than two of its horizontal, vertical and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

1, 7, 45, 302, 1648, 7594, 31152, 119656, 446500, 1658080, 6210762, 23592940, 90908854, 354490210, 1394647332, 5520750316

Offset

1,2

Comments

Diagonal of A280604.

Links

Table of n, a(n) for n=1..16.

Example

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

Crossrefs

Cf. A280604.

Sequence in context: A182556 A363570 A219020 * A301319 A143835 A103719

Adjacent sequences: A280594 A280595 A280596 * A280598 A280599 A280600

Keyword

nonn

Author

R. H. Hardin, Jan 06 2017

Status

approved