Dirichlet Structure Constant
where
is the Fundamental Unit and 
is the number of substitutions which leave the binary quadraticform unchanged
See also Class Number, Dirichlet L-Series
References
Weisstein, E. W. ``Class Numbers.'' Mathematica notebook ClassNumbers.m.
- Brocard Axis
- Brocard Circle
- Brocard Diameter
- Brocard Line
- Brocard Midpoint
- Brocard Points
- Brocard's Conjecture
- Brocard's Problem
- Brocard Triangles
- Bromwich Integral
- Brothers
- Brouwer Fixed Point Theorem
- Browkin's Theorem
- Brown Function
- Brown Numbers
- Brown's Criterion
- Broyden's Method
- Bruck-Ryser-Chowla Theorem
- Bruck-Ryser Theorem
- Brunnian Link
- Brunn-Minkowski Inequality
- Brun's Constant
- Brun's Sum
- Brun's Theorem
- Brute Force Factorization