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.

A300826 a(n) = n/A125746(n), where A125746(n) gives the smallest divisor d of n such that the sum which includes d and all smaller divisors is >= n.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 1, 1, 2, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 1, 2, 1, 2, 1
Offset: 1

Views

Author

Antti Karttunen, Mar 21 2018

Keywords

Comments

Records occur at 1, 6, 24, 120, 240, 504, 1260, 2520, 5040, 15120, 50400, 55440, ... and they are 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, ...

Crossrefs

Cf. A125746.
Cf. A005100 (positions of ones), A023196 (positions of terms > 1).

Programs

  • PARI
    A300826(n) = { my(k=0,s=0); fordiv(n,d, k++; s += d; if(s>=n,return(n/d))); };

Formula

a(n) = n/A125746(n).