A280281 Number of nX4 0..2 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

2, 384, 16860, 592416, 18844474, 566131860, 16393550046, 462579750172, 12805032188772, 349269067529316, 9415514952577460, 251409624519315024, 6660091714490230910, 175258485314498284648, 4585645730057094995818

Offset

1,1

Comments

Column 4 of A280284.

Links

R. H. Hardin, Table of n, a(n) for n = 1..176

Example

Some solutions for n=3
..0..1..2..0. .0..1..0..2. .0..1..2..0. .0..1..0..1. .0..1..2..0
..0..2..1..1. .0..1..1..2. .1..0..2..1. .2..2..0..2. .0..1..2..0
..0..1..0..0. .2..2..0..1. .1..1..0..1. .0..1..0..1. .2..1..0..1

Crossrefs

Cf. A280284.

Sequence in context: A142532 A329555 A171431 * A225096 A225111 A343698

Adjacent sequences: A280278 A280279 A280280 * A280282 A280283 A280284

Keyword

nonn

Author

R. H. Hardin, Dec 30 2016

Status

approved