For n >= 2 a(n) <= [log_2(n)] with equality if n=2^m is a power of 2. a(n) = 1 iff n belongs to sequence A003277.
Table of n, a(n) for n=0..16.
a(8) = 3 because there are two non-Abelian groups of order 8, both generated by two elements and the Abelian group Z2xZ2xZ2 that is generated by 3 elements. So a(8) = 3
Sequence in context: A107456 A165112 A077480 * A076558 A204893 A057217
Adjacent sequences: A059826 A059827 A059828 * A059830 A059831 A059832
Noam Katz (noamkj(AT)hotmail.com), Feb 25 2001