A328860 - OEIS

%I #36 Feb 17 2020 09:31:59

%S 993803899780063855042560,2028353759451110328141864960,

%T 6476620014866676143312363520

%N Numbers that are 4-imperfect.

%H Douglas E. Iannucci, <a href="http://www.integers-ejcnt.org/g41/g41.Abstract.html">On a variation of perfect numbers</a>, INTEGERS: Electronic Journal of Combinatorial Number Theory, 6 (2006), #A41.

%H Andrew Lelechenko, <a href="/A127724/a127724_1.txt">4-imperfect numbers</a>, Apr 19 2014.

%H Michel Marcus, <a href="/A127724/a127724_2.txt">More 4-imperfect numbers</a>, Nov 07 2017.

%H Michel Marcus, <a href="/A309806/a309806.gp.txt">solveIMP PARI script</a>

%H Michel Marcus, <a href="/A328860/a328860.txt">List of 4-imperfect numbers</a> (including the 2 files above), last edit Jun 2019.

%H Weiyi Zhou and Long Zhu, <a href="http://www.emis.de/journals/INTEGERS/papers/j1/j1.Abstract.html">On k-imperfect numbers</a>, INTEGERS: Electronic Journal of Combinatorial Number Theory, 9 (2009), #A01.

%o (PARI) solveIMP(1, 4, 10^24)

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

%Y Cf. A309806 (the k values).

%Y Cf. A206369 (the rho function).

%K nonn,more,bref

%O 1,1

%A _Michel Marcus_, Feb 16 2020