%I #5 Mar 30 2012 17:26:03
%S 3,1,1,7,9,2,5,1,13,15,17,19,21,4,3,1,25,27,5,1,2,13,33,35,19,18,39,
%T 41,43,7,17,47,49,51,53,55,57,59,61,39,3,65,67,69,71,35,38,75,77,79,
%U 81,47,1,85,87,89,23,17,71,10,12,95,97,99,101,103,5,65,107,109,4,11,113,115
%N Numerator of 1/pp(n) - 1/pp(n+1), where pp(n) = n-th prime power.
%e a(2) = 1 because 1/pp(3) - 1/pp(2) = 1/4 - 1/8 =1/2.
%K easy,nonn,frac
%O 1,1
%A _Zak Seidov_, Oct 11 2002