OFFSET
2,2
COMMENTS
Challenge: find the smallest n for which pi(n) < a(n), where pi(n) is the prime counting function.
LINKS
Arkadiusz Wesolowski, Table of n, a(n) for n = 2..10000
Wikipedia, Prime number theorem
MATHEMATICA
Table[Round[LogIntegral[n] - LogIntegral@Sqrt[n]], {n, 2, 74}]
PROG
(PARI) a(n)=round(real(eint1(-log(n)/2)-eint1(-log(n)))) \\ Charles R Greathouse IV, Feb 27 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Arkadiusz Wesolowski, Feb 27 2013
STATUS
approved