OFFSET
1,1
LINKS
Douglas E. Iannucci, On a variation of perfect numbers, INTEGERS: Electronic Journal of Combinatorial Number Theory, 6 (2006), #A41.
Andrew Lelechenko, 4-imperfect numbers, Apr 19 2014.
Michel Marcus, More 4-imperfect numbers, Nov 07 2017.
Michel Marcus, solveIMP PARI script
Michel Marcus, List of 4-imperfect numbers (including the 2 files above), last edit Jun 2019.
Weiyi Zhou and Long Zhu, On k-imperfect numbers, INTEGERS: Electronic Journal of Combinatorial Number Theory, 9 (2009), #A01.
PROG
(PARI) solveIMP(1, 4, 10^24)
CROSSREFS
KEYWORD
nonn,more,bref
AUTHOR
Michel Marcus, Feb 16 2020
STATUS
approved