cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-1 of 1 results.

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

Original entry on oeis.org

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

Views

Author

Labos Elemer, Jul 17 2000

Keywords

Crossrefs

Programs

  • Mathematica
    Table[PrimeNu[EulerPhi[Prime[n]!]], {n, 1, 50}] (* G. C. Greubel, May 13 2017 *)
  • PARI
    for(n=1,50, print1(omega(eulerphi(prime(n)!)) , ", ")) \\ G. C. Greubel, May 13 2017

Formula

a(n) = A001221(A055929(n)).
Showing 1-1 of 1 results.