OFFSET
1,4
FORMULA
For prime p, a(p^i) = 2^(p^(i-1)-1).
MATHEMATICA
<< DiscreteMath`Combinatorica`; f[n_] := Plus @@ Table[ Count[ KSubsets[ Range[n], k], q_List /; Chop[ -1 + Plus @@ (E^((2.*Pi*I*q)/n))] === 0], {k, 0, n}]; Table[ f[n], {n, 24}] (* Robert G. Wilson v, Jun 03 2005 *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
T. D. Noe, May 23 2005
STATUS
approved