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A107609 a(n) = round(n / pi(n)) = round(A000027(n) / A000720(n)). 4

%I #20 Aug 21 2021 13:12:29

%S 2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,2,3,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,

%T 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,3,4,3,3,4,4,4,4,4,4,4,

%U 4,4,4,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4

%N a(n) = round(n / pi(n)) = round(A000027(n) / A000720(n)).

%C This sequence grows very slowly. The first n for which a(n) = 5 is 190, then 556 for 6, 1821 for 7, etc. - _Alonso del Arte_, Feb 27 2012

%e a(6) = 2 because pi(6) = 3 and 6/3 = 2.

%e a(7) = 2 because pi(7) = 4 and 7/4 = 1.75, which rounds up to 2.

%t Table[ Round[ n / PrimePi[ n]], {n, 2, 106}]

%Y Cf. A000720, A107610, A107614, A272231.

%K nonn

%O 2,1

%A _Jonathan Vos Post_ and _Robert G. Wilson v_, May 17 2005

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