1,2

pi(n) denotes the number of positive primes not exceeding n.

sigma(49)-phi(49) = 15 = pi(49), so 49 is a term of the sequence.

Sequence in context: A041523 A054206 A063777 this_sequence A061185 A012199 A062961

Adjacent sequences: A067785 A067786 A067787 this_sequence A067789 A067790 A067791

nonn

Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Feb 06 2002