A066887 Numbers k such that Omega(phi(k)) = Omega(k) where phi is the Euler totient function and Omega(k) is the number of repeated prime factors in k.

1, 3, 9, 10, 14, 20, 22, 27, 28, 30, 40, 42, 44, 46, 50, 56, 60, 66, 80, 81, 84, 88, 90, 92, 94, 98, 100, 112, 118, 120, 126, 132, 138, 150, 160, 166, 168, 176, 180, 184, 188, 196, 198, 200, 214, 224, 236, 240, 242, 243, 250, 252, 264, 270, 276, 282, 294, 300, 320

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harry J. Smith)

Mathematica

Select[Range[300], PrimeOmega[EulerPhi[#]] == PrimeOmega[#] &] (* Amiram Eldar, May 19 2022 *)

Prog

(PARI) { n=0; for (m=1, 10^10, if(bigomega(eulerphi(m)) == bigomega(m), n++; print1(m, ", "); if (n==1000, return)) ) } \\ Harry J. Smith, Apr 04 2010

Crossrefs

Cf. A000010, A001222, A343911.

Sequence in context: A229269 A363954 A050852 * A030608 A118515 A191339

Adjacent sequences: A066884 A066885 A066886 * A066888 A066889 A066890

Keyword

nonn

Author

Benoit Cloitre, Jan 26 2002

Extensions

a(1) = 1 inserted by Amiram Eldar, May 19 2022

Status

approved