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A065858 m-th composite number c(m) = A002808(m), where m is the n-th prime number: a(n) = A002808(A000040(n)).

%I A065858 #21 Mar 09 2025 12:40:13
%S A065858 6,8,10,14,20,22,27,30,35,44,46,54,58,62,66,75,82,85,92,96,99,108,114,
%T A065858 120,129,134,136,142,144,148,166,171,178,182,194,196,204,210,215,221,
%U A065858 230,232,245,247,252,254,268,285,289,291,296,302,304,318,324,330,338
%N A065858 m-th composite number c(m) = A002808(m), where m is the n-th prime number: a(n) = A002808(A000040(n)).
%C A065858 Composites (A002808) with prime (A000040) subscripts. a(n) U A175251(n) = A002808(n). Subsequence of A022449 (composites (A002808) with noncomposite (A008578) subscripts), a(n) = A022449(n+1). - _Jaroslav Krizek_, Mar 14 2010
%H A065858 Robert Israel, <a href="/A065858/b065858.txt">Table of n, a(n) for n = 1..10000</a>
%p A065858 P,C:= selectremove(isprime,[seq(i,i=2..10^3)]):
%p A065858 seq(C[P[i]],i=1..100); # _Robert Israel_, Mar 09 2025
%t A065858 Composite[n_] := FixedPoint[n + PrimePi[#] + 1 & , n + PrimePi[n] + 1];
%t A065858 a[n_] := Composite[Prime[n]];
%t A065858 Array[a, 100] (* _Jean-François Alcover_, Jan 26 2018, after _Robert G. Wilson v_ *)
%Y A065858 Cf. A002808, A000040, A008578, A022449, A065856, A065857, A175251.
%K A065858 nonn
%O A065858 1,1
%A A065858 _Labos Elemer_, Nov 26 2001