OFFSET
1,1
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..6368 (all terms below 2*10^11, from David Moews' site).
Peter Hagis, Jr., Bi-unitary amicable and multiperfect numbers, Fibonacci Quarterly, Vol. 25, No. 2 (1987), pp. 144-150.
David Moews, Perfect, amicable and sociable numbers.
MATHEMATICA
fun[p_, e_]:=If[Mod[e, 2]==1, (p^(e+1)-1)/(p-1), (p^(e+1)-1)/(p-1)-p^(e/2)];
bsigma[n_] := If[n==1, 1, Times @@ (fun @@@ FactorInteger[n])]; Do[s = bsigma[n]; If[s > 2 n && bsigma[s - n] == s, Print[n]], {n, 1, 10000}] (* Amiram Eldar, Sep 29 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Sep 27 2017
STATUS
approved