A208098 Number of 3 X n nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal, diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).

1, 5, 34, 1573, 169064, 34438557, 11535531783, 5804338800147, 4121852595871393, 3947133396896179889, 4923290609971869799119, 7783034938833777039389506, 15253558021465456746321690675, 36391805974300638618769192592189, 104086634920105554145003030677202100

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..100

Example

Some solutions for n=4:
..0..1..0..2....0..1..0..1....0..1..2..0....0..1..0..1....0..1..0..1
..3..1..0..2....0..1..0..1....0..1..2..0....0..2..3..1....0..1..0..1
..0..1..0..1....2..1..2..1....0..1..2..0....0..1..0..4....0..1..0..1

Crossrefs

Row 3 of A208096.

Sequence in context: A309534 A348375 A194687 * A216759 A144995 A173865

Adjacent sequences: A208095 A208096 A208097 * A208099 A208100 A208101

Keyword

nonn

Author

R. H. Hardin, Feb 23 2012

Extensions

a(0)=1 prepended and terms a(9) and beyond from Andrew Howroyd, May 17 2020

Status

approved