1,1

Successive numbers k such that EulerPhi[x]/x = m

( Family of sequences for successive n odd primes )

m=2/3 numbers with exactly 1 distinct prime divisor {3} see A000244

m=8/15 numbers with exactly 2 distinct prime divisors {3,5} see A033849

m=16/35 numbers with exactly 3 distinct prime divisors {3,5,7} see A147576

m=32/77 numbers with exactly 4 distinct prime divisors {3,5,7,11} see A147577

m=384/1001 numbers with exactly 5 distinct prime divisors {3,5,7,11,13} see A147578

m=6144/17017 numbers with exactly 6 distinct prime divisors {3,5,7,11,13,17} see A147579

m=3072/323323 numbers with exactly 7 distinct prime divisors {3,5,7,11,13,17,19} see A147580

m=110592/323323 numbers with exactly 8 distinct prime divisors {3,5,7,11,13,17,19,23} see A147581

a = {}; Do[If[EulerPhi[x]/x == 384/1001, AppendTo[a, x]], {x, 1, 1000000}]; a(*Artur Jasinski*)

A060735, A143207, A147571-A147575, A147576-A147580

Sequence in context: A112643 A129485 A133778 this_sequence A151595 A124047 A113008

Adjacent sequences: A147575 A147576 A147577 this_sequence A147579 A147580 A147581

nonn

Artur Jasinski (grafix(AT)csl.pl), Nov 07 2008