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 A165689 Numbers n such that pi(n) = (1/10)*n. 0

%I

%S 64540,64580,64610,64620,64650,64690,64700,64710,64720

%N Numbers n such that pi(n) = (1/10)*n.

%C A subsequence of A057809. For each positive integer m, set of the numbers n such that pi(n)=(1/10^m)*n is a finite set. I guess that all these sets are nonempty. What is the smallest number n such that pi(n) = (1/100)*n?

%t Select[10 Range[10000], PrimePi[ # ] == 1/10 # &]

%o (PARI) forcomposite(n=1, 1e5, if(10*primepi(n) == n, print1(n, ", "))) \\ _Altug Alkan_, Dec 18 2015

%Y Cf. A057809.

%K fini,full,nonn

%O 1,1

%A _Farideh Firoozbakht_, Oct 06 2009

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