The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A327160 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A327160

Number of positive integers that are reachable from n with some combination of transitions x -> usigma(x)-x and x -> gcd(x,usigma(x)), where usigma is the sum of unitary divisors of n (A034448).
(history; published version)

#15 by N. J. A. Sloane at Mon Aug 26 12:51:45 EDT 2019

STATUS

proposed

approved

#14 by Antti Karttunen at Sun Aug 25 16:20:24 EDT 2019

STATUS

editing

proposed

#13 by Antti Karttunen at Sun Aug 25 16:18:59 EDT 2019

CROSSREFS

Cf. A034448, A034460, A318882, A323166.

Cf. also A318882, A326198, A327161.

#12 by Antti Karttunen at Sun Aug 25 16:05:17 EDT 2019

COMMENTS

Question: Is this sequence well defined for all every n ? If A318882 is not well defined in whole N, then neither this can be.

#11 by Antti Karttunen at Sun Aug 25 16:04:20 EDT 2019

EXAMPLE

From n = 30 we can reach any of the following strictly positive numbers: 30 (e.g., with an empty sequence of transitions), 42 (as A034460(30) = 42), 54 (as A034460(42) = 54; note that A034460(54) = 30 again) and 6 as A323166(30) = A323166(42) = A323166(54) = 6 = A323166(6), = A034460(6), thus a(30) = 4.

#10 by Antti Karttunen at Sun Aug 25 16:01:38 EDT 2019

EXAMPLE

#9 by Antti Karttunen at Sun Aug 25 15:33:57 EDT 2019

COMMENTS

Question: Is this sequence well defined for all n ? If A318882 is not well defined, in whole N, then neither this iscan be.

#8 by Antti Karttunen at Sun Aug 25 15:21:02 EDT 2019

COMMENTS

This Question: Is this sequence is well defined for all n > 1 provided that ? If A318882 is not well defined (all its terms have finite values), then neither this is.

#7 by Antti Karttunen at Sun Aug 25 15:09:37 EDT 2019

COMMENTS

Question: Is this This sequence is well defined for all n ?> 1 provided that A318882 is well defined (all its terms have finite values).

#6 by Antti Karttunen at Sun Aug 25 14:56:36 EDT 2019

COMMENTS

Question: Is this sequence well defined for all n ?