OFFSET
1,2
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..100
MATHEMATICA
limit = 200000; sums = Accumulate[EulerPhi[Range[limit]]]; Select[Range[limit], Mod[sums[[#]], EulerPhi[#]] == 0 &] (* Carl Najafi, Sep 05 2011 *)
PROG
(PARI) isok(n)=sum(k=1, n, eulerphi(k))%eulerphi(n)==0 \\ Anders Hellström, Aug 22 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Carl Najafi, Sep 04 2011
EXTENSIONS
More terms from D. S. McNeil, Sep 04 2011
STATUS
approved