The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A141377 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A141377

a(n) = the smallest positive integer non-coprime to both n and d(n), where d(n) is the number of divisors of n.
(history; published version)

#9 by Michael De Vlieger at Sat Feb 18 08:08:37 EST 2023

STATUS

proposed

approved

#8 by Antti Karttunen at Sat Feb 18 05:47:06 EST 2023

STATUS

editing

proposed

#7 by Antti Karttunen at Sat Feb 18 05:46:48 EST 2023

LINKS

Antti Karttunen, <a href="/A141377/b141377.txt">Table of n, a(n) for n = 2..16385</a>

PROG

(PARI) A141377(n) = { my(d=numdiv(n)); for(k=2, oo, if(gcd(k, n)>1 && gcd(k, d)>1, return(k))); }; \\ Antti Karttunen, Feb 18 2023

STATUS

approved

editing

#6 by Charles R Greathouse IV at Wed Apr 09 10:15:04 EDT 2014

AUTHOR

Leroy Quet , Jun 28 2008

Discussion

Wed Apr 09

10:15

OEIS Server: https://oeis.org/edit/global/2150

#5 by N. J. A. Sloane at Wed Feb 05 20:18:48 EST 2014

AUTHOR

_Leroy Quet _ Jun 28 2008

Discussion

Wed Feb 05

20:18

OEIS Server: https://oeis.org/edit/global/2118

#4 by Russ Cox at Fri Mar 30 17:29:56 EDT 2012

EXTENSIONS

Extended by _Ray Chandler (rayjchandler(AT)sbcglobal.net), _, Jun 24 2009

Discussion

Fri Mar 30

17:29

OEIS Server: https://oeis.org/edit/global/154

#3 by N. J. A. Sloane at Sat Oct 02 03:00:00 EDT 2010

LINKS

Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> (listed in lieu of email address)

KEYWORD

nonn,new

nonn

#2 by N. J. A. Sloane at Tue Jun 01 03:00:00 EDT 2010

DATA

2, 6, 6, 10, 2, 14, 2, 3, 2, 22, 2, 26, 2, 6, 10, 34, 2, 38, 2, 6, 2, 46, 2, 15, 2, 6, 2, 58, 2, 62, 2, 6, 2, 10, 3, 74, 2, 6, 2, 82, 2, 86, 2, 3, 2, 94, 2, 21, 2, 6, 2, 106, 2, 10, 2, 6, 2, 118, 2, 122, 2, 3, 14, 10, 2, 134, 2, 6, 2, 142, 2, 146, 2, 3, 2, 14, 2, 158, 2, 15, 2, 166, 2, 10, 2, 6

KEYWORD

more,nonn,new

nonn

EXTENSIONS

Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Jun 24 2009

#1 by N. J. A. Sloane at Fri Jan 09 03:00:00 EST 2009

NAME

a(n) = the smallest positive integer non-coprime to both n and d(n), where d(n) is the number of divisors of n.

DATA

2, 6, 6, 10, 2, 14, 2, 3, 2, 22, 2, 26, 2, 6, 10

OFFSET

2,1

LINKS

Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> (listed in lieu of email address)

FORMULA

a(n) = A141327(n, A000005(n)).

CROSSREFS

Cf. A141327, A141378, A141379.

KEYWORD

more,nonn

AUTHOR

Leroy Quet Jun 28 2008

STATUS

approved