A068276 1/9 the number of colorings of an n X n rhombic hexagonal array with 9 colors.

1, 392, 5765144, 3181273031384, 65865666949993359176, 51166369594150205333793355592, 1491342760953091009621584639091222226600, 1630938910749494351643174313469316936138973479205208

Offset: 1

Author

R. H. Hardin, Feb 24 2002

Keywords

• nonn

Comments

Terms for rhombic- and staggered- hexagonal arrays are the same for n in 1..4.

Crossrefs

Cf. A068239-A068305, A000332, A002417, A027441, A212162, A212163.

Extensions

a(6)-a(8) from Alois P. Heinz, May 02 2012