1,1

200286975596707184640 belongs to this sequence. [From Gerard P. Michon (g.michon(AT)att.net), May 10 2009]

81703797123392614369698250752 is in this sequence. [From Gerard P. Michon (g.michon(AT)att.net), May 11 2009]

G. P. Michon, Table of n, a(n) for n=1..27

G. P. Michon, Multiperfect and hemiperfect integers [From Gerard P. Michon (g.michon(AT)att.net), Jun 04 2009]

Walter Nissen, Abundancy : Some Resources

Walter Nissen, Home Page (listed in lieu of email address)

Cf. A055153, A141643, A159271, A160678.

Cf. A159907 = (half-integer abundancy) [From Gerard P. Michon (g.michon(AT)att.net), May 10 2009]

Sequence in context: A015378 A151936 A078143 this_sequence A151933 A162021 A157815

Adjacent sequences: A141642 A141643 A141644 this_sequence A141646 A141647 A141648

nonn

Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp), May 10 2008

Definition rewritten by M. F. Hasler, May 10 2008

Is it certain that there are no other terms below the highest value shown? - N. J. A. Sloane (njas(AT)research.att.com), Sep 07 2008

Corrected a(1), confirmed a(3) - Ray Chandler (rayjchandler(AT)sbcglobal.net), Sep 18 2008

Missing term a(2)= 17428320 communicated by Walter Nissen Apr 17 2009. There are no further terms through 2^34.

Missing term a(4) inserted and a(6) and a(8) added by Grzegorz Lach (137.036(AT)gmail.com), Apr 18 2009. a(4) was also sent by Avinoam Kalma (a.kalma(AT)gmail.com), Apr 20 2009.

a(7) = 15338300494970880 added by Gerard P. Michon (g.michon(AT)att.net), May 10 2009.

a(10)=215594611071909888000 [and above] from Michel Marcus, added by Gerard P. Michon (g.michon(AT)att.net), Jun 04 2009