A computation has been made of the noncyclic class groups of imaginary quadratic fields Q(√-D) for even and odd discriminants - D from 0 to - 25000000. Among the results are that 95% of the class groups are cyclic, and that -11203620 and -18397407 are the first discriminants of imaginary quadratic fields for which the class group has rank three in the 5-Sylow subgroup. The latter was known to be of rank three; this computation demonstrates that it is the first odd discriminant of 5-rank three or more.
Published in Mathematics of Computation, Volume 48, Issue 177, 1987, pages 85-93.
Buell, D.A. (1987). Class groups of quadratic fields II. Mathematics of Computation. 48(177), 85-93.
First published in Mathematics of Computation in 1987, published by the American Mathematical Society.
Copyright ©1987 American Mathematical Society.