5162224

Appears in sequences

• Number of n-bead necklaces with 4 colors.at n=13A001868
• Number of subsets of {1,2,3,...,n} that sum to 0 mod 13.at n=26A068034
• a(n) = -(1/n) * Sum_{d|n} phi(n/d) * (-4)^d.at n=12A343466