A216660 Number of horizontal, vertical or knight-move neighbor colorings of an nX2 array with new integer colors introduced in row major order

1, 4, 25, 279, 4800, 116635, 3760019, 153831836, 7730921915, 465562795125, 32949873078160, 2698248029796465, 252407175864930849, 26685021081300144340

Offset

1,2

Comments

Column 2 of A216663

Links

Table of n, a(n) for n=1..14.

Example

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

Crossrefs

Sequence in context: A361589 A320569 A058791 * A352859 A374851 A350585

Adjacent sequences: A216657 A216658 A216659 * A216661 A216662 A216663

Keyword

nonn

Author

R. H. Hardin Sep 13 2012

Status

approved