OFFSET
1,2
COMMENTS
Primitive parts of A002605.
LINKS
Eric Weisstein's World of Mathematics, Sylvester Cyclotomic Number.
FORMULA
a(n) = A002605(n)/A105606(n); a(n) = product{k=1..n-1, if(gcd(n, k)=1, (1+sqrt(3))-(1-sqrt(3))*exp(2*Pi*I*k/n), 1)}, I=sqrt(-1). - Robert G. Wilson v, Aug 02 2005
MATHEMATICA
f[n_] := FullSimplify[ Expand[ Times @@ ((1+Sqrt[3])-(1-Sqrt[3])*Exp[2Pi*I*Select[Range[n], GCD[ #, n] == 1 &]/n])]]; Table[ f[n], {n, 2, 32] (* Robert G. Wilson v, Aug 02 2005 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul Barry, Apr 15 2005
EXTENSIONS
More terms from David Wasserman, May 06 2008
STATUS
approved