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%I #10 Feb 21 2014 11:52:36
%S 3,4,6,8,11,12,15,16,19,23,24,29,30,31,34,37,40,42,46,47,47,51,53,56,
%T 61,62,63,66,66,68,75,77,80,80,86,87,91,93,95,97,99,100,105,106,107,
%U 108,115,121,123,124,125,127,128,133,136,138,139,141,145
%N Greatest k such that k-th prime < 3 times n-th prime.
%H Harvey P. Dale, <a href="/A020901/b020901.txt">Table of n, a(n) for n = 1..1000</a>
%t Table[PrimePi[NextPrime[3Prime[n],-1]],{n,60}] (* _Harvey P. Dale_, Feb 21 2014 *)
%o (PARI) a(n) = primepi(3*prime(n)) \\ _Michel Marcus_, Mar 22 2013
%Y Cf. A020900, A020934-A020940.
%K nonn
%O 1,1
%A _Clark Kimberling_
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