OFFSET
0,2
LINKS
Daniel Suteu, Table of n, a(n) for n = 0..27
Eric Weisstein's World of Mathematics, Riemann Prime Counting Function
FORMULA
EXAMPLE
0, 16/3, 428/15, 445273/2520, 56175529/45045, 991892879/102960, 18296822833013/232792560, ...
PROG
(PARI) a(n) = denominator(sum(k=1, logint(10^n, 2), primepi(sqrtnint(10^n, k))/k));
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
Daniel Suteu, Dec 24 2018
STATUS
approved