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A111181 Prime(n) - Pi(n). 2

%I #8 Nov 21 2013 12:48:44

%S 2,2,3,5,8,10,13,15,19,25,26,32,35,37,41,47,52,54,59,63,65,71,74,80,

%T 88,92,94,98,99,103,116,120,126,128,138,140,145,151,155,161,166,168,

%U 177,179,183,185,196,208,212,214,218,224,225,235,241,247,253,255,260,264

%N Prime(n) - Pi(n).

%C Conjecture: There will always be an x such that a(x+1) - a(x) = k for k=1,2.. However, x becomes large when k > 70.

%H Charles R Greathouse IV, <a href="/A111181/b111181.txt">Table of n, a(n) for n = 1..10000</a>

%F Prime(n) = the n-th prime. Pi(x) = number of primes <= x.

%t Table[Prime[n]-PrimePi[n],{n,60}] (* _Harvey P. Dale_, Mar 11 2012 *)

%o (PARI) primexmpix(n,k) = { local(x,y,z); for(x=1,n, y=prime(x)-primepi(x); z=prime(x+1)-primepi(x+1); if(z-y == k,print1(y",") ) ) }

%o (PARI) a(n)=prime(n)-primepi(n) \\ _Charles R Greathouse IV_, May 29 2013

%K easy,nonn

%O 1,1

%A _Cino Hilliard_, Oct 22 2005

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Last modified July 22 00:58 EDT 2024. Contains 374478 sequences. (Running on oeis4.)