The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A054021 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A054021

Numbers n such that Chowla's function of n is divisible by the number of proper divisors of n.
(history; published version)

#12 by N. J. A. Sloane at Fri Oct 27 22:00:46 EDT 2023

AUTHOR

_Asher Auel (asher.auel(AT)reed.edu), _, Jan 19 2000

Discussion

Fri Oct 27

22:00

OEIS Server: https://oeis.org/edit/global/2974

#11 by Bruno Berselli at Wed Aug 28 03:56:34 EDT 2019

STATUS

reviewed

approved

#10 by Joerg Arndt at Wed Aug 28 03:23:34 EDT 2019

STATUS

proposed

reviewed

#9 by Michel Marcus at Wed Aug 28 03:06:23 EDT 2019

STATUS

editing

proposed

#8 by Michel Marcus at Wed Aug 28 03:06:20 EDT 2019

CROSSREFS

Complement is A054020 Cf. A032741, A048050, A054015.

Cf. A032741, A048050, A054015.

AUTHOR

Asher Auel (asher.auel(AT)reed.edu) , Jan 19, 2000

STATUS

proposed

editing

#7 by Amiram Eldar at Wed Aug 28 02:59:13 EDT 2019

STATUS

editing

proposed

#6 by Amiram Eldar at Wed Aug 28 02:39:13 EDT 2019

LINKS

Amiram Eldar, <a href="/A054021/b054021.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

approved

editing

#5 by Harvey P. Dale at Mon Aug 13 20:06:05 EDT 2018

STATUS

editing

approved

#4 by Harvey P. Dale at Mon Aug 13 20:06:02 EDT 2018

MATHEMATICA

Select[Range[2, 150], Divisible[DivisorSigma[1, #]-1-#, DivisorSigma[ 0, #]-1]&] (* Harvey P. Dale, Aug 13 2018 *)

STATUS

approved

editing

#3 by N. J. A. Sloane at Sun Feb 20 03:00:00 EST 2005

NAME

Numbers n such that Chowla 's function of n is divisible by the number of proper divisors of n.

KEYWORD

nonn,new

nonn