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.

Previous Showing 11-11 of 11 results.

A216897 a(n) = smallest m such that sigma(m)/m = n + 1/3.

Original entry on oeis.org

3, 12, 1080, 18506880, 2198278051200, 28657168334177779210174055055360000, 30539655646420783598362725995379113771515252254037575464371359842304000000000
Offset: 1

Views

Author

Michel Marcus, Sep 19 2012

Keywords

Comments

a(7) is a 77-digit number with factorization: 2^35 3^20 5^9 7^3 11 13^2 17 19 23 29 31 37^2 41 61 67 71 73 109 137 409 521 547 1093 36809 368089.
An upper bound for a(8) is a 165-digit number that can be found on given link where line begins with 25/3.

Examples

			a(1) = 3 because sigma(3)/3 = 4/3 = 1 + 1/3 and 3 is the earliest m such that sigma(m)/m = 1 + 1/3.

Links

Crossrefs

Cf. A160320, A088912.

Extensions

a(7) confirmed and added by Max Alekseyev, Jun 06 2025
Previous Showing 11-11 of 11 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.