A068288 1/9 the number of colorings of an n X n staggered hexagonal array with 9 colors.

1, 392, 5765144, 3181273031384, 65865668592143803208, 51166372312341376389944811656, 1491342882335672198457853495232503998152, 1630939089590623060636571472516037785233254346536136, 66921448813902442793929754551432219305219935812987218443538247160

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, A212194, A212195.

Extensions

a(6)-a(9) from Alois P. Heinz, May 03 2012