OFFSET
1,1
COMMENTS
These are a proper subset of the primes of the form x^2+32y^2 whose class numbers are divisible by 8.
REFERENCES
Cohn, H. Introduction to the construction of class fields, Cambridge, 1985, pp. 147-151
LINKS
Philip A. Leonard and Kenneth S. Williams, On the divisibility of the class numbers of Q(sqrt(-p)) and Q(sqrt(-2p)) by 16, Canadian Math Bulletin,v.25 (1982), pp. 200-6.
EXAMPLE
h(-257)=16: binary quadratic forms of discriminant -4(257) are x^2+257y^2, 2x^2+2xy+129y^2, 3x^2+-2xy+86y^2, 6x^2+-2xy+43y^2,9x^2+-4xy+29y^2, 7x^2+-6xy+38y^2, 14x^2+-6xy+19y^2, 13x^2+-8xy+21y^2, 17x^2+-14xy+18y^2 for 16 forms (the +- forms count twice)
CROSSREFS
KEYWORD
nonn
AUTHOR
John L. Drost, Apr 30 2005
STATUS
approved