The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A124441 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A124441

a(n) = Product_{1<=k<=n/2, gcd(k,n)=1} k.
(history; published version)

#26 by Ray Chandler at Fri Nov 01 09:35:56 EDT 2019

STATUS

editing

approved

#25 by Ray Chandler at Fri Nov 01 09:35:53 EDT 2019

MATHEMATICA

f[n_] := Times @@ Select[Range[Floor[n/2]], GCD[ #, n] == 1 &]; Table[f[n], {n, 36}] (* Ray Chandler , Nov 12 2006 *)

STATUS

approved

editing

#24 by Jon E. Schoenfield at Fri Oct 18 00:17:36 EDT 2019

STATUS

editing

approved

#23 by Jon E. Schoenfield at Fri Oct 18 00:17:28 EDT 2019

NAME

a(n) = productProduct_{1<=k<=n/2, GCDgcd(k,n)=1} k.

STATUS

approved

editing

#22 by Bruno Berselli at Fri Feb 06 04:48:14 EST 2015

STATUS

proposed

approved

#21 by Michel Marcus at Fri Feb 06 03:29:04 EST 2015

STATUS

editing

proposed

#20 by Michel Marcus at Fri Feb 06 03:28:29 EST 2015

COMMENTS

A124441a(n) divides A001783(n). - M. F. Hasler, Jul 23 2011

LINKS

J. B. Cosgrave and K. Dilcher, <a href="http://www.integers-ejcntemis.orgde/journals/INTEGERS/papers/i39/vol8i39.Abstract.html">Extensions of the Gauss-Wilson Theorem</a>, Integers: Electronic Journal of Combinatorial Number Theory, 8 (2008)

FORMULA

A124441a(n) = A001783(n)/A124442(n). - M. F. Hasler, Jul 23 2011

MATHEMATICA

f[n_] := Times @@ Select[Range[Floor[n/2]], GCD[ #, n] == 1 &]; Table[f[n], {n, 36}] (* _Ray Chandler_ *)

PROG

(PARI) A124441(n)=prod(k=2, n\2, k^(gcd(k, n)==1)) \\ - _ _M. F. Hasler_, Jul 23 2011

STATUS

approved

editing

#19 by Charles R Greathouse IV at Wed Apr 09 10:16:40 EDT 2014

AUTHOR

Leroy Quet , Nov 01 2006

Discussion

Wed Apr 09

10:16

OEIS Server: https://oeis.org/edit/global/2155

#18 by N. J. A. Sloane at Wed Feb 05 20:18:29 EST 2014

AUTHOR

_Leroy Quet _ Nov 01 2006

Discussion

Wed Feb 05

20:18

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

#17 by Alois P. Heinz at Wed Oct 03 10:05:13 EDT 2012

STATUS

editing

approved