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.

A329039 If n = Product p_i^e_i, a(n) = n * Sum ((e_i - 1)/p_i).

Original entry on oeis.org

0, 0, 0, 2, 0, 0, 0, 8, 3, 0, 0, 6, 0, 0, 0, 24, 0, 6, 0, 10, 0, 0, 0, 24, 5, 0, 18, 14, 0, 0, 0, 64, 0, 0, 0, 30, 0, 0, 0, 40, 0, 0, 0, 22, 15, 0, 0, 72, 7, 10, 0, 26, 0, 36, 0, 56, 0, 0, 0, 30, 0, 0, 21, 160, 0, 0, 0, 34, 0, 0, 0, 96, 0, 0, 15, 38, 0, 0, 0, 120, 81, 0, 0, 42, 0, 0, 0, 88, 0, 30, 0, 46, 0, 0, 0, 192, 0, 14, 33, 70, 0, 0, 0, 104, 0
Offset: 1

Views

Author

Antti Karttunen, Nov 07 2019

Keywords

Crossrefs

Cf. A005117 (positions of zeros).

Programs

  • PARI
    A329039(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, ((f[i, 2]-1)/f[i, 1])));

Formula

a(n) = A003415(n) - A069359(n).