We answer the question, ``For what permutation groups G ≤ Sn do G and a random permutation σ generate the symmetric or the alternating group?'' Extending Dixon's result, we prove that this is the case if and only if G fixes o(n) elements of the permutation domain.
The question arose in connection with the study of the diameter of Cayley graphs of the symmetric group.
Our proof is based on a result by Łuczak and Pyber on the structure of random permutations.
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