A064452 Integers which are not primes or powers of primes such that for all j>i Phi(j)/j > Phi(i)/i.

6, 10, 14, 15, 21, 33, 35, 55, 65, 77, 91, 119, 133, 143, 187, 209, 221, 247, 299, 323, 391, 437, 493, 527, 551, 589, 667, 713, 851, 899, 1073, 1147, 1189, 1247, 1271, 1333, 1457, 1517, 1591, 1739, 1763, 1927, 2021, 2173, 2279, 2419, 2491, 2623, 2747, 2773

Offset

1,1

Links

Table of n, a(n) for n=1..50.

Mathematica

a = 0; Do[ If[ Length[ FactorInteger[n]] > 1 && EulerPhi[n]/n > a, a = EulerPhi[n]/n; Print[n]], {n, 1, 5000} ]

Crossrefs

Sequence in context: A088709 A225706 A063078 * A085647 A072901 A371811

Adjacent sequences: A064449 A064450 A064451 * A064453 A064454 A064455

Keyword

easy,nonn

Author

Robert G. Wilson v, Oct 02 2001

Status

approved