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.

A258847 Sum of the k-th pi-based arithmetic derivative of n-k for k=0..n.

Original entry on oeis.org

0, 1, 2, 4, 6, 10, 13, 20, 21, 33, 54, 86, 146, 339, 788, 2947, 14870, 94801, 706961, 5566784, 43958933, 317950465, 2406052444, 19645433193, 146175038733, 1479263447899, 16135114175706, 203382520812382, 2606355260220040, 32974597626726301, 406609097787758227
Offset: 0

Views

Author

Alois P. Heinz, Jun 12 2015

Keywords

Crossrefs

Antidiagonal sums of A258850.

Programs

  • Maple
    with(numtheory):
    d:= n-> n*add(i[2]*pi(i[1])/i[1], i=ifactors(n)[2]):
    A:= proc(n, k) option remember; `if`(k=0, n, d(A(n, k-1))) end:
    a:= proc(n) option remember; add(A(h, n-h), h=0..n) end:
    seq(a(n), n=0..30);

Formula

a(n) = Sum_{k=0..n} A258850(n-k,k).