The signature of Gamma(+)(0)(n)

The signature of T-0(+)(eN(2)), where e is square free, is completely deter mined if e = 3 or N is odd or e is an element of Psi, where Psi is the set of all square free integers e is an element of N such that (i) if e is odd, then e admits no divisors of the form 8k + 3, (ii) if e is even, then e admits no divisors of the form 8k + 7. In particular, nu (2) (number of elliptic classes of period 2 of Gamma (+)( 0)(n)) is expressed as a linear combination of multiplicative functions. (C ) 2001 Academic Press.