A068268 1/18 the number of colorings of an n X n square array with 18 colors.

1, 4641, 5554571857, 1714419367669298289, 136461767759964622690609683537, 2801124263786734144622842493797034683405617, 14827953377838619886793709359009173477911476430325930106481, 20242190237452646688395985657256161903754274932459524235140863308223305109841

Offset: 1

Author

R. H. Hardin, Feb 24 2002

Keywords

• nonn

Crossrefs

Cf. A068239-A068305, A000332, A002417, A027441, A182368, A182406.

Extensions

a(5)-a(8) from Alois P. Heinz, Apr 27 2012