OFFSET
0,2
COMMENTS
Sequence is interesting because the initial terms seem to have many small factors.
FORMULA
a(n) = 2 cos(pi (n+1)/3) binomial(n+7,7). Note that 2 cos(pi (n+1)/3) is always 1, -1, 2, or -2, so this formula explains the small factors. - Dean Hickerson, Feb 06 2006
CROSSREFS
KEYWORD
sign
AUTHOR
Creighton Dement, Dec 06 2005
STATUS
approved