OFFSET
1,2
LINKS
MATHEMATICA
f[n_] := 2 n - DivisorSigma[1, n]; Array[DivisorSum[#, f, f@ # >= 0 &] &, 92] (* Michael De Vlieger, Sep 04 2018 *)
PROG
(PARI) A318678(n) = sumdiv(n, d, d=d+d-sigma(d); (d>0)*d);
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 04 2018
STATUS
approved