[seqfan] Re: Are sequences like A015762 finite?

Harvey P. Dale hpd at hpdale.org
Mon Aug 21 22:20:33 CEST 2017

	There are no further terms up to 3 million.

-----Original Message-----
From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of Alonso Del Arte
Sent: Monday, August 21, 2017 11:44 AM
To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
Subject: [seqfan] Are sequences like A015762 finite?

A015762 consists of numbers n such that phi(n) divides sigma_4(n). These are the numbers listed:

1, 2, 3, 6, 249, 498

Harvey's 2012 Mathematica program only goes up to 500, but can easily be changed to go much higher than that. I've taken it up to 10000 and found no further terms.

Intuition is no substitute for proof, but no proof suggests itself to me at the moment. My intuition tells me that this sequence is finite.

There are very similar sequences in its immediate neighborhood of A-numbers.


Alonso del Arte
Author at SmashWords.com
Musician at ReverbNation.com <http://www.reverbnation.com/alonsodelarte>

Seqfan Mailing list - http://list.seqfan.eu/

More information about the SeqFan mailing list