A207999 Number of nX3 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any knight-move neighbor (colorings ignoring permutations of colors).

5, 114, 4141, 426422, 86545486, 29169661126, 14823734802701, 10648697150313375, 10321527909363771779, 13032394645031912097587, 20852865726433378283251197, 41354508341339617041441302471, 99804566252370862012176094395266, 288659258928461717629676421776606809

Offset

1,1

Links

Andrew Howroyd, Table of n, a(n) for n = 1..50

Example

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

Crossrefs

Column 3 of A208001.

Sequence in context: A091026 A346273 A216342 * A223057 A208783 A089638

Adjacent sequences: A207996 A207997 A207998 * A208000 A208001 A208002

Keyword

nonn

Author

R. H. Hardin, Feb 22 2012

Extensions

Terms a(8) and beyond from Andrew Howroyd, Jul 01 2017

Status

approved