A281656 Number of 4Xn 0..2 arrays with no element equal to more than one 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, 384, 10572, 135444, 1887730, 23075928, 270969324, 3113195344, 34971286598, 386653964892, 4223141414822, 45663070459288, 489646946151752, 5214047221217132, 55193564929148884, 581272228367033168

Offset

1,2

Comments

Row 4 of A281653.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Example

Some solutions for n=4
..0..1..1..2. .0..1..0..2. .0..0..1..1. .0..1..0..2. .0..1..0..2
..2..2..0..2. .2..1..2..2. .2..1..2..1. .0..2..2..2. .2..1..0..1
..0..1..0..0. .1..0..0..1. .0..1..2..0. .0..2..0..0. .2..2..0..1
..0..2..2..1. .1..2..1..2. .1..0..2..1. .0..2..1..1. .1..1..2..1

Crossrefs

Cf. A281653.

Sequence in context: A134241 A203980 A061403 * A128967 A168675 A190401

Adjacent sequences: A281653 A281654 A281655 * A281657 A281658 A281659

Keyword

nonn

Author

R. H. Hardin, Jan 26 2017

Status

approved