OFFSET
1,1
MATHEMATICA
fQ[n_] := DivisorSigma[1, n] == 2 n + 128; Select[ Range@ 10^8, fQ] (* Robert G. Wilson v, Nov 19 2017 *)
PROG
(PARI) isok(n) = sigma(n) - 2*n == 128; \\ Michel Marcus, Sep 20 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Fabian Schneider, Sep 20 2017
EXTENSIONS
a(9)-a(18) from Michel Marcus, Sep 20 2017
a(19)-a(28) from Robert G. Wilson v, Nov 20 2017
STATUS
approved