The Quadratic Hash Method When the Table Size Is Not a Prime Number
Previous work on quadratic hash methods is
limited mainly to the case where the table size 
is a prime number.  Here, certain results are derived for
composite numbers.  It is shown that all composite 
numbers containing at least the square of one of the component
primes have full-period integer-coefficient 
quadratic hash functions.
CACM April, 1975
Batagelj, V.
