A068272 1/5 the number of colorings of an n X n rhombic hexagonal array with 5 colors.

1, 36, 6588, 6169500, 29607951492, 728359861595076, 91850117930957987604, 59375832328440271451653884, 196759041550650648492160100067468, 3342365125469959463321258123750822068332, 291049545090789051667036543236086657649935910108

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(8)-a(9) from Alois P. Heinz, May 02 2012

a(10)-a(11) from Andrew Howroyd, Jun 25 2017