A182283 Number of triangular n X n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any neighbor.

1, 1, 15, 3429, 18172005, 3030361658604, 20538495213667066533, 7069329642959332230532689983, 150574890630606350105309341350824904669, 237075065354315062816111131522815337395866137560373, 32430625006159571889921247597353572731767630164652210957593666925

Offset

1,3

Links

Table of n, a(n) for n=1..11.

Example

Some solutions for n=4
.....0........0........0........0........0........0........0........0
....1.2......1.2......1.2......1.2......1.2......1.2......1.2......1.2
...2.0.3....3.4.0....2.0.1....0.3.4....3.4.0....3.4.0....3.4.5....3.4.0
..3.1.4.1..4.2.5.4..3.1.3.0..4.5.2.5..0.5.3.6..4.5.3.6..5.0.2.1..1.2.3.5

Crossrefs

Cf. A182797, A193283.

Sequence in context: A013720 A230672 A145189 * A194479 A262019 A153832

Adjacent sequences: A182280 A182281 A182282 * A182284 A182285 A182286

Keyword

nonn

Author

R. H. Hardin, Apr 23 2012

Extensions

a(7)-a(11) from Andrew Howroyd, Apr 23 2018

Status

approved