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.

A258650 Tenth arithmetic derivative of n.

Original entry on oeis.org

0, 0, 0, 0, 4, 0, 0, 0, 8592, 0, 0, 0, 20096, 0, 0, 3424, 70464, 0, 0, 0, 16304, 0, 0, 0, 32624, 0, 1520, 27, 70464, 0, 0, 0, 235072, 0, 0, 8592, 47872, 0, 0, 20096, 24640, 0, 0, 0, 65264, 8592, 0, 0, 130544, 0, 3424, 8144, 47872, 0, 57996, 20096, 198656, 0, 0
Offset: 0

Views

Author

Alois P. Heinz, Jun 06 2015

Keywords

Crossrefs

Column k=10 of A258651.
Cf. A003415.

Programs

  • Maple
    d:= n-> n*add(i[2]/i[1], i=ifactors(n)[2]):
    A:= proc(n, k) option remember; `if`(k=0, n, d(A(n, k-1))) end:
    a:= n-> A(n, 10):
    seq(a(n), n=0..70);
  • Python
    from sympy import factorint
    def A258650(n):
        for _ in range(10):
            if n <= 1: return 0
            n = sum((n*e//p for p,e in factorint(n).items()))
        return n # Chai Wah Wu, Nov 03 2022

Formula

a(n) = A003415^10(n).