%I #3 Oct 01 2013 17:58:21
%S 2,3,2,2,2,2,3,2,2,3,2,3,2,2,3,2,3,2,2,3,2,2,2,2,3,2,2,2,2,3,2,2,2,2,
%T 3,2,2,2,2,3,2,2,3,2,3,2,2,3,2,3,2,2,3,2,3,2,2,3,2,2,2,2,3,2,2,2,2,3,
%U 2,2,2,2,3,2,2,2,2,3,2,2,3,2,3,2,2,3,2,3,2,2,3,2,3,2,2,3,2,2,2,2
%N Difference between successive terms of floor(10^n/Li(10^n)  1).
%C 10^n/Li(10^n)  1) is the ratio of estimated composite numbers less than 10^n to the estimated prime numbers less than 10^n. Conjecture: 2 and 3 are the only numbers in this sequence.
%F Li(n) is the logarithmic integral which approximates the number of primes less than n. n Li(n) = Int dt/log(t) 2
%o (PARI) LiRatioDiff(m,n) = { local(x,p1,p2,a,b); forstep(x=m,n,2, p1=10.^x; p2=10^(x+1); a=floor(p1/Li(p1)1); b=floor(p2/Li(p2)1); print1(ba,",") ) } Li(x) = \ Logarithmic integral { eint1(log(1/x)) }
%K easy,nonn
%O 1,1
%A _Cino Hilliard_, Nov 16 2005
