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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
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 (list; graph; refs; listen; history; text; internal format)
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
Sequence in context: A229269 A363954 A050852 * A030608 A118515 A191339
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jan 26 2002
EXTENSIONS
a(1) = 1 inserted by Amiram Eldar, May 19 2022
STATUS
approved

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Last modified March 29 05:43 EDT 2024. Contains 371264 sequences. (Running on oeis4.)