The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A049532

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A049532

Numbers k such that k^2 + 1 is not squarefree.
(history; published version)

#49 by Charles R Greathouse IV at Thu Sep 08 08:44:58 EDT 2022

PROG

(MAGMAMagma) [n: n in [1..6*10^2]| not IsSquarefree(n^2+1)]; // Bruno Berselli, Oct 15 2012

Discussion

Thu Sep 08

08:44

OEIS Server: https://oeis.org/edit/global/2944

#48 by Susanna Cuyler at Wed Jul 08 08:06:22 EDT 2020

STATUS

proposed

approved

#47 by Amiram Eldar at Wed Jul 08 02:24:11 EDT 2020

STATUS

editing

proposed

#46 by Amiram Eldar at Wed Jul 08 02:14:59 EDT 2020

COMMENTS

A059592(a(n)) > 1; A124809(n) = a(n)^2 + 1. - Reinhard Zumkeller, Nov 08 2006

The asymptotic density of this sequence is 1 - A335963 = 0.1051587754... - Amiram Eldar, Jul 08 2020

FORMULA

A059592(a(n)) > 1; A124809(n) = a(n)^2 + 1. - Reinhard Zumkeller, Nov 08 2006

CROSSREFS

Cf. A002522, A059592, A124809, A335963.

STATUS

approved

editing

#45 by Bruno Berselli at Mon May 28 09:13:17 EDT 2018

STATUS

proposed

approved

#44 by Jon E. Schoenfield at Mon May 28 09:07:23 EDT 2018

STATUS

editing

proposed

#43 by Jon E. Schoenfield at Mon May 28 09:07:14 EDT 2018

NAME

Numbers n k such that nk^2 + 1 is not squarefree.

COMMENTS

The sequence is infinite. For instance, it contains all numbers of the form 7 + 25m. - Emmanuel Vantieghem, Oct 25 2016

STATUS

approved

editing

#42 by Michael Somos at Tue Oct 25 21:18:01 EDT 2016

STATUS

proposed

approved

#41 by Wesley Ivan Hurt at Tue Oct 25 12:53:13 EDT 2016

STATUS

editing

proposed

#40 by Wesley Ivan Hurt at Tue Oct 25 12:52:54 EDT 2016

CROSSREFS

Cf. A002522, A059592, A124809.

STATUS

proposed

editing