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ABSTRACT: Using techniques described in , we have computed the class number and class group structure of all imaginary quadratic
fields with discriminant Δ for 0 11. A novel verification algorithm based on the Eichler Selberg Trace Formula  was used to ensure that the correctness of
our results does not rely on any unproved hypothesis. We present the results of our computations, and remark on specific evidence
that was found pertaining to a number of heuristics. In particular, we present data which supports some of the Cohen-Lenstra
heuristics , Littlewood’s bounds on L(1,χ) , and Bach’s bound on the maximum norm of the prime ideals required to generate the class group .
Algorithmic Number Theory, 7th International Symposium, ANTS-VII, Berlin, Germany, July 23-28, 2006, Proceedings; 01/2006