OFFSET
1,1
COMMENTS
Question: Are all terms of this sequence even? (Compare A065557, whose terms could be all odd and squarefree.)
LINKS
Harry J. Smith and Jud McCranie, Table of n, a(n) for n = 1..494 (first 117 terms from Harry J. Smith)
EXAMPLE
phi(8) = 4 = 6-2 = phi(7) - phi(6).
MATHEMATICA
Flatten[Position[Partition[EulerPhi[Range[630000]], 3, 1], _?(#[[3]] == #[[2]]- #[[1]]&), 1, Heads->False]]+2 (* Harvey P. Dale, Aug 19 2018 *)
PROG
(PARI) n=0; for (m=3, 10^9, if (eulerphi(m) == eulerphi(m - 1) - eulerphi(m - 2), write("b066231.txt", n++, " ", m); if (n==117, return)) ) \\ Harry J. Smith, Feb 06 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Dec 18 2001
EXTENSIONS
a(24)-a(36) from Harry J. Smith, Feb 06 2010
STATUS
approved