An integer d is a fundamental discriminant if it is not equal to 1, not divisible by any square of any odd prime, and satisfies d congruent 1 (mod 4) or d congruent 8, 12 (mod 16). The function FundamentalDiscriminantQ[d] in the Wolfram Language version 5.2 add-on package NumberTheoryˋNumberTheoryFunctionsˋ tests if an integer d is a fundamental discriminant. The first few positive fundamental discriminants are 5, 8, 12, 13, 17, 21, 24, 28, 29, 33, ... (OEIS A003658). Similarly, the first few negative fundamental discriminants are -3, -4, -7, -8, -11, -15, -19, -20, -23, -24, -31, ... (OEIS A003657).

class number | Dirichlet L-series | discriminant | regulator