OFFSET
1,1
COMMENTS
The restriction phi(k) != phi(k+1) is intended to exclude all the (trivial) terms of A001274.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..200
MATHEMATICA
s[n_]:=Plus @@ FixedPointList[EulerPhi, n] - (n + 1); seqQ[n_]:=(s[n+1]==s[n])&&(EulerPhi[n+1]!=EulerPhi[n]); Select[Range[10^5], seqQ]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Aug 19 2017
STATUS
approved