The On-Line Encyclopedia of Integer Sequences (OEIS)

The OEIS is supported by the many generous donors to the OEIS Foundation.

Revision History for A166069

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

A166069

Multiply perfect numbers k such that sigma(k)/k > 2.
(history; published version)

#16 by Joerg Arndt at Sun Mar 17 02:12:21 EDT 2024

STATUS

editing

approved

#15 by Paolo P. Lava at Sat Mar 16 15:16:29 EDT 2024

MAPLE

with(numtheory); P:=proc(q) local a, n;

for n from 1 to q do a:=sigma(n)/n; if type(a, integer) and a>2 then print(n);

fi; od; end: P(10^6); # Paolo P. Lava, Oct 24 2013

STATUS

approved

editing

#14 by Bruno Berselli at Thu Nov 14 09:39:20 EST 2019

STATUS

proposed

approved

#13 by Michel Marcus at Thu Nov 14 09:22:09 EST 2019

STATUS

editing

proposed

#12 by Michel Marcus at Thu Nov 14 09:22:04 EST 2019

LINKS

Achim Flammenkamp, <a href="http://wwwwwwhomes.uni-bielefeld.de/~achim/mpn.html">The Multiply Perfect Numbers Page</a>

STATUS

approved

editing

#11 by Joerg Arndt at Thu Oct 24 12:02:51 EDT 2013

STATUS

proposed

approved

#10 by Michel Marcus at Thu Oct 24 08:50:49 EDT 2013

STATUS

editing

proposed

#9 by Michel Marcus at Thu Oct 24 08:50:44 EDT 2013

LINKS

Achim Flammenkamp, <a href="http://www.uni-bielefeld.de/~achim/mpn.html">The Multiply Perfect Numbers Page</a>

PROG

(PARI) isok(n) = sn = sigma(n)/n ; (type(sn) == "t_INT") && (sn > 2); \\ Michel Marcus, Oct 24 2013

STATUS

proposed

editing

#8 by Paolo P. Lava at Thu Oct 24 07:00:17 EDT 2013

STATUS

editing

proposed

#7 by Paolo P. Lava at Thu Oct 24 07:00:13 EDT 2013

MAPLE

with(numtheory); P:=proc(q) local a, n;

for n from 1 to q do a:=sigma(n)/n; if type(a, integer) and a>2 then print(n);

fi; od; end: P(10^6); # Paolo P. Lava, Oct 24 2013

STATUS

approved

editing