login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A028500 12-hyperperfect numbers: n = 12*(sigma(n)-n-1) + 1. 3
697, 2041, 1570153, 62722153, 10604156641, 13544168521, 1792155938521 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(8) > 4*10^12. 7056410014866537089009269921 is also a term. - Donovan Johnson, Nov 20 2012

LINKS

Table of n, a(n) for n=1..7.

J. S. McCranie, A study of hyperperfect numbers, J. Int. Seqs. Vol. 3 (2000) #P00.1.3

Eric Weisstein's World of Mathematics, Hyperperfect Number

CROSSREFS

Cf. A000396, A007593, A220290, A028499, A028501-A028502, A034916.

Sequence in context: A137559 A185377 A118059 * A133251 A243837 A116338

Adjacent sequences:  A028497 A028498 A028499 * A028501 A028502 A028503

KEYWORD

hard,more,nonn

AUTHOR

Jud McCranie

EXTENSIONS

a(7) from Donovan Johnson, Nov 20 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified December 20 09:29 EST 2014. Contains 252241 sequences.