On Central Gap Numbers of Symmetric Groups

g(G) denotes the central gap number of a group G. We show that for n ≥ 8, g(Sn) ≥ n and g(An) ≥ n-2. We give exact values of g(Sn) and g(An) for small n's. In particular, g(S9) = 9 and g(A9) = 7. Therefore, for any positive integer n ≠ 1, 3, 5 there is a group G such that n = g(G). G can be finite or infinite.