

A166362


a(n) = phi(nonprime(n)).


1



1, 2, 2, 4, 6, 4, 4, 6, 8, 8, 6, 8, 12, 10, 8, 20, 12, 18, 12, 8, 16, 20, 16, 24, 12, 18, 24, 16, 12, 20, 24, 22, 16, 42, 20, 32, 24, 18, 40, 24, 36, 28, 16, 30, 36, 32, 48, 20, 32, 44, 24, 24, 36, 40, 36, 60, 24, 32, 54, 40, 24, 64, 42, 56, 40, 24, 72, 44, 60, 46, 72, 32, 42, 60
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OFFSET

1,2


COMMENTS

Here 1, 4, 6, 8, 9, 10, 12, 14, 15, 16,.. are the nonprimes A018252. Or, unit together with EulerPhi of nth composite number (i.e. A073256).


LINKS

G. C. Greubel, Table of n, a(n) for n = 1..10000


MATHEMATICA

Table[EulerPhi[FixedPoint[n + PrimePi@# &, n + PrimePi@n]], {n, 1, 100}] (* G. C. Greubel, May 10 2016 *)


CROSSREFS

Cf. A000010, A073256, A018252.
Sequence in context: A286542 A278973 A073256 * A050469 A085730 A232065
Adjacent sequences: A166359 A166360 A166361 * A166363 A166364 A166365


KEYWORD

nonn,look


AUTHOR

JuriStepan Gerasimov, Oct 12 2009


EXTENSIONS

Entries checked by R. J. Mathar, May 21 2010


STATUS

approved



