OFFSET
1,1
LINKS
Michel Marcus, Table of n, a(n) for n = 1..117
G. P. Michon and M. Marcus, Hemiperfect numbers of abundancy 11/2 (table with factorizations). [From Gerard P. Michon, Jul 01 2009]
Walter Nissen, Abundancy : Some Resources
PROG
(PARI) is(n)=sigma(n, -1)==11/2 \\ Charles R Greathouse IV, Mar 09 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
M. F. Hasler, Apr 21 2009
STATUS
approved