A163161 - OEIS

%I #3 Mar 31 2012 10:31:26

%S 5,9,14,30,44,47,64,67,72,89,99,124,125,194,198,200,208,213,214,249,

%T 267,270,320,333,372,373,374,393,455,460,475,519,586,603,643,701,704,

%U 712,770,774,789,814,825,828,836,891,906,930,941,970,974,982,983,988,1022

%N Values of n at which the sequence A161865/A161867 equals 1/2.

%C The corresponding sequence for primes is A144264, and the ratio is given by sequences A161621/A161622.

%t t1 = Table[ ((2n+1) - (PrimePi[(n+1)^2] - PrimePi[n^2]))/((4n+4)- (PrimePi[(n+2)^2] - PrimePi[n^2])), {n,1,100}]; t2= Position[t1, 1/2]; [From _Daniel Tisdale_, Jul 24 2009]

%K nonn

%O 1,1

%A _Daniel Tisdale_, Jul 21 2009, Jul 24 2009

%E Corrected by the author, Jul 25 2009

%E Extended beyond 194 by _R. J. Mathar_, Sep 27 2009