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A068283
1/4 the number of colorings of an n X n staggered hexagonal array with 4 colors.
1
1, 12, 264, 11424, 1009608, 185900256, 71883991272, 58646051219616, 101273697848025960, 370689919380760915680, 2880341312871966116331528, 47562687666338563715921774496
OFFSET
1,2
COMMENTS
Terms for rhombic- and staggered- hexagonal arrays are the same for n in 1..4.
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 24 2002
EXTENSIONS
a(9) from Alois P. Heinz, May 03 2012
a(10)-a(12) from Sean A. Irvine, Feb 07 2024
STATUS
approved