A328860 Numbers that are 4-imperfect.

993803899780063855042560, 2028353759451110328141864960, 6476620014866676143312363520

Offset: 1

Author

Michel Marcus, Feb 16 2020

Keywords

• nonn
• more
• bref

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.

Crossrefs

Cf. A127724 (k-imperfect), A127725 (2-imperfect), A127726 (3-imperfect).

Cf. A309806 (the k values).

Cf. A206369 (the rho function).

Programs

PARI

solveIMP(1, 4, 10^24)