La Jolla Cyclic Difference Set Repository
A (v,k,lambda) cyclic difference set is a subset D = {d_1, d_2, ..., d_k}
of the integers modulo v such that {1,2,...,v-1} can each be represented
as a difference (d_i - d_j) modulo v in exactly lambda different ways.
This page gives information about possible parameters for cyclic
difference sets.
Here is a list of known
difference sets in
postscript and in
pdf.
The LJDSR tables list
parameters with k<=300 which satisfy
simple necessary conditions, with status (known difference sets, proof
of nonexistence, or open).
Here are some papers on difference sets and the Prime
Power Conjecture.
If you know of any difference sets not listed here, or proofs that
any open cases don't exist,
please send email to Dan Gordon at
gordon@ccrwest.org.
Go to Dan Gordon's home page