OFFSET
1,2
COMMENTS
The PARI script is good up to n=9. The last 3 terms were computed by the gcc 4.1.2 program in the link. A good approximation for the n-th term is R(10^n+10^(n-1))-R(10^n) where R(x) is Riemann's approximation of the number of prime numbers < x. This is included in the PARI script. for example, Rpr11(12) = 3612792548.5108.., accurate for the first 6 digits.
LINKS
Cino Hilliard, Count primes in a range.
Cino Hilliard, Count primes in a range up to 10^18, message 58 in seqfun Yahoo group, providing code for gcc (needs formatting to become compilable), Sep 23, 2007. [Cached copy]
EXAMPLE
For n=2, the 4 primes in the range 100 to 110 are 101,103,107,109. So 4 is the second entry in the sequence.
PROG
(PARI) /*Some functions*/ pr11(n) = primepi(10^n+10^(n-1))-primepi(10^n) Rpr11(n) = R(10^n+10^(n-1))-R(10^(n)) R(x) = local(j); (sum(j=1, 400, moebius(j)*Li(x^(1/j))/j)) /*End functions*/ for(x=1, 9, print1(pr11(x), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Cino Hilliard, Sep 23 2007
EXTENSIONS
a(13)-a(19) from Hugo Pfoertner, Nov 16 2019
a(20)-a(21) from Chai Wah Wu, Nov 29 2019
a(22) from Chai Wah Wu, Nov 30 2019
STATUS
approved