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.

A129132 Partial sums of A051903.

Original entry on oeis.org

0, 1, 2, 4, 5, 6, 7, 10, 12, 13, 14, 16, 17, 18, 19, 23, 24, 26, 27, 29, 30, 31, 32, 35, 37, 38, 41, 43, 44, 45, 46, 51, 52, 53, 54, 56, 57, 58, 59, 62, 63, 64, 65, 67, 69, 70, 71, 75, 77, 79, 80, 82, 83, 86, 87, 90, 91, 92, 93, 95, 96, 97, 99, 105, 106, 107, 108, 110, 111, 112
Offset: 1

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Author

Reinhard Zumkeller, Mar 30 2007

Keywords

Crossrefs

Programs

  • Mathematica
    f[1] = 0; f[n_] := Max @ FactorInteger[n][[;; , 2]]; Accumulate @ Array[f, 70] (* Amiram Eldar, Oct 19 2020 *)

Formula

a(n+1) = a(n) + A051903(n), a(1) = 0;
A128651(a(n-1) + 2) = A007947(n) for n>1.
a(n) ~ c * n, where c is Niven's constant (A033150). - Amiram Eldar, Oct 19 2020
a(n) = - Sum_{i=2..n} Sum_{j=1..n} mobius(i)*floor(n/(i^j)). - Ridouane Oudra, Nov 22 2024