A055930 Number of distinct prime factors of totient of (n-th prime)!.

0, 1, 1, 2, 3, 3, 4, 4, 5, 6, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 11, 12, 13, 14, 15, 15, 15, 16, 16, 16, 18, 18, 19, 19, 21, 21, 21, 22, 23, 23, 24, 24, 24, 24, 25, 25, 27, 29, 30, 30, 30, 30, 30, 30, 31, 32, 32, 32, 33, 34, 34, 34, 36, 36, 36, 37, 38, 39, 40, 40, 40, 41, 42, 42

Offset

1,4

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Formula

a(n) = A001221(A055929(n)).

Mathematica

Table[PrimeNu[EulerPhi[Prime[n]!]], {n, 1, 50}] (* G. C. Greubel, May 13 2017 *)

Prog

(PARI) for(n=1, 50, print1(omega(eulerphi(prime(n)!)) , ", ")) \\ G. C. Greubel, May 13 2017

Crossrefs

Cf. A001221, A039716.

Sequence in context: A171975 A160511 A079952 * A090638 A247908 A057363

Adjacent sequences: A055927 A055928 A055929 * A055931 A055932 A055933

Keyword

nonn

Author

Labos Elemer, Jul 17 2000

Status

approved