Published online by Cambridge University Press: 20 November 2018
0. Notation. Throughout this paper p denotes a prime congruent to 1 modulo 4. It is well known that such primes are expressible in an essentially unique manner as the sum of the squares of two integers, that is,
(0.1)
with |a| and |b| uniquely determined by (0.1). Since a is odd, replacing a by –a if necessary, we can specify a uniquely by
(0.2)
Further, as {[(p – l)/2]!}2 = – 1 (mod p), we can specify b uniquely by
(0.3)
These choices are assumed throughout.
The following notation is also used throughout the paper: h(d) denotes the class number of the quadratic field of discriminant d, (d/n) is the Kronecker symbol of modulus |d|, [x] denotes the greatest integer less than or equal to the real number x, and {x} = x – [x].