A330412 Integers m such that sigma(m) + sigma(8*m) = 18*m.

34, 568, 147328, 603971584, 9663643648, 39582416502784, 696341272098017608537735168, 765635325572111542783369494684623699968, 3615610599582728119969414707766982030374842621310535527825408, 3791242500068058721125048996612134914443116117566314438843154038784

Offset

1,1

Comments

This is the case h = 8 of the h-perfect numbers as defined in the Harborth link.

Links

Table of n, a(n) for n=1..10.

Heiko Harborth, On h-perfect numbers, Annales Mathematicae et Informaticae, 41 (2013) pp. 57-62.

Formula

a(n) = 2^A002236(n) * A050524(n).

Example

34 is a term since sigma(34) + sigma(8*34) = 612, that is 18*34.

Prog

(PARI) isok(m) = sigma(m) + sigma(8*m) == 18*m;

Crossrefs

Cf. A000203, A000396, A002236, A050524, A136539, A281993, A330413.

Sequence in context: A232320 A133720 A010950 * A089938 A126924 A035712

Adjacent sequences: A330409 A330410 A330411 * A330413 A330414 A330415

Keyword

nonn

Author

Jinyuan Wang, Feb 12 2020

Status

approved