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.

User: Kam Kong

Kam Kong's wiki page.

Kam Kong has authored 1 sequences.

A349049 Number of prime factors (with multiplicity) of the denominator of the harmonic number H(n) = Sum_{k=1..n} 1/k.

Original entry on oeis.org

0, 1, 2, 3, 4, 3, 4, 5, 7, 7, 8, 8, 9, 9, 9, 10, 11, 10, 11, 10, 9, 9, 10, 11, 13, 13, 15, 15, 16, 16, 17, 18, 17, 17, 17, 17, 18, 18, 18, 18, 19, 18, 19, 20, 20, 20, 21, 21, 23, 23, 23, 23, 24, 23, 23, 23, 23, 23, 24, 24, 25, 25, 24, 25, 25, 24, 25, 25, 26, 26, 27, 28, 29, 29, 29, 29, 28
Offset: 1

Author

Kam Kong, Nov 07 2021

Keywords

Crossrefs

Programs

  • PARI
    my(h=0); for(n=1,77,h+=1/n;print1(bigomega(denominator(h)),", ")); \\ Joerg Arndt, Nov 07 2021
    
  • Python
    from sympy import harmonic, factorint
    def a(n): return sum(factorint(harmonic(n).denominator).values())
    print([a(n) for n in range(1, 78)]) # Michael S. Branicky, Nov 07 2021
  • SageMath
    [sloane.A001222(A002805(n)) for n in range(1, 78)]
    

Formula

a(n) = A001222(A002805(n)).