1,2
Complement of A112588.
Eric Weisstein's World of Mathematics, Totient Function
Eric Weisstein's World of Mathematics, Divisor Function
Cf. A020488.
Sequence in context: A193988 A124455 A072378 * A141820 A068090 A094222
Adjacent sequences: A112584 A112585 A112586 * A112588 A112589 A112590
nonn,fini,full
Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Sep 14 2005