Hi
before I reinvent the wheel, has anyone coded up the Legendre symbol  
(a/p)?
[
If p is an odd prime number and a is an integer, then the Legendre  
symbol
(a/p)   is:
     * 0 if p divides a;
     * 1 if a is a square modulo p ? that is to say there exists an  
integer k such that k^2 ? a (mod p)
     * ?1 if not
[courtesy Wikipedia]
]
I might also need Jacobi's generalization of this.
--
Robin Hankin
Uncertainty Analyst
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
  tel  023-8059-7743