A145260 1/9 of the number of 9-colorings of an n X n array symmetric under 180 degree rotation.

1, 8, 3256, 1319648, 27265229496, 560946752022448

Offset

1,2

Links

Table of n, a(n) for n=1..6.

Crossrefs

Sequence in context: A217270 A137565 A281323 * A201100 A079177 A298279

Adjacent sequences: A145257 A145258 A145259 * A145261 A145262 A145263

Keyword

nonn

Author

R. H. Hardin, Oct 05 2008

Status

approved