%I #24 Mar 26 2023 02:18:13

%S 2,6,8,10,60,70,128,136,9822,18632,32768,32896,36720,69726,73662,

%T 73686,73734,85962,86046,87114,87198,87222,87258,87294,87306,87342,

%U 87366,87546,87558,88014,88278,88302,88338,88386,127326,128046,128082,128382,128406,128598,128802

%N Numbers k for which A064380(k) = k/2.

%C Note that, if there exist infinitely many infinitary perfect numbers (A007357), then, as k tends to infinity over such numbers, A064380(k)/k = 1/2 + o(k^(-1+eps)). We conjecture that here A064380(k)/k = 1/2 infinitely many times, and thus the sequence contains infinitely many infinitary perfect numbers.

%H Amiram Eldar, <a href="/A185078/b185078.txt">Table of n, a(n) for n = 1..201</a>

%Y Cf. A064380, A007357, A064380, A185373, A185383.

%K nonn

%O 1,1

%A _Vladimir Shevelev_, Feb 18 2011

%E a(7)-a(13) from _Amiram Eldar_, Sep 13 2019

%E a(14)-a(41) from _Amiram Eldar_, Mar 26 2023