A216790 Number of 4-colorings of a side-n hexagonal array with colors introduced in row major order

1, 11, 5318, 22831676, 915294166360, 348567447145791344

Offset

1,2

Comments

Column 3 of A216792

Links

Table of n, a(n) for n=1..6.

Example

Some solutions for n=3
......0.1.2..........0.1.2..........0.1.2..........0.1.2..........0.1.2
.....1.3.0.1........1.2.0.3........3.2.3.0........3.2.0.1........3.2.3.0
....3.2.1.2.0......0.3.1.2.1......2.0.1.2.1......2.0.3.2.3......2.1.0.2.1
.....0.3.0.3........1.0.3.0........3.2.0.3........1.2.0.1........0.2.1.3
......2.1.2..........3.1.2..........0.3.2..........0.1.3..........1.3.0

Crossrefs

Sequence in context: A147668 A177804 A023334 * A068730 A257124 A208857

Adjacent sequences: A216787 A216788 A216789 * A216791 A216792 A216793

Keyword

nonn

Author

R. H. Hardin Sep 16 2012

Status

approved