OFFSET
1,1
MATHEMATICA
ad[1] = 0; ad[n_] := n * Total@(Last[#]/First[#]& /@ FactorInteger[n]); Select[Range[270], Divisible[ad[DivisorSigma[1, #]] - #, 3] &] (* Amiram Eldar, Sep 18 2021 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 18 2021
STATUS
approved