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.

A300719 Difference between A003557 (n divided by largest squarefree divisor of n) and its Möbius transform.

Original entry on oeis.org

0, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 4, 1, 3, 1, 2, 1, 1, 1, 4, 1, 1, 3, 2, 1, 1, 1, 8, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 2, 3, 1, 1, 8, 1, 5, 1, 2, 1, 9, 1, 4, 1, 1, 1, 2, 1, 1, 3, 16, 1, 1, 1, 2, 1, 1, 1, 8, 1, 1, 5, 2, 1, 1, 1, 8, 9, 1, 1, 2, 1, 1, 1, 4, 1, 3, 1, 2, 1, 1, 1, 16, 1, 7, 3, 6, 1, 1, 1, 4, 1
Offset: 1

Views

Author

Antti Karttunen, Mar 12 2018

Keywords

Crossrefs

Programs

  • PARI
    A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = max(0,f[i, 2]-1)); factorback(f); }; \\ From A003557
    A300719(n) = -sumdiv(n,d,(dA003557(d));

Formula

a(n) = -Sum_{d|n, dA008683(n/d)*A003557(d).
a(n) = A003557(n) - A300717(n).