A160503 - OEIS

%I #22 Apr 03 2023 10:36:11

%S 2,5,2,1229,2,2,664579,3,2,97,19,2,11,2,19,5,3,2,23,2,2,2,73,2,2,7,3,

%T 2,3

%N Least prime divisor of pi(10^n).

%H C. Caldwell's Prime Pages, <a href="https://t5k.org/howmany.shtml#table">A Table of values of pi(x)</a>.

%F a(n) = A020639(A006880(n)).

%e a(1)=2 because under 10^1 there are 4 primes, and least prime divisor = 2.

%e a(4)=1229 because under 10^4 there are 1229 primes and that number, being prime, is its own least prime divisor.

%Y Cf. A006880, A141306.

%K nonn,more

%O 1,1

%A _Enoch Haga_, May 16 2009

%E Edited by _Ray Chandler_, May 20 2009

%E a(24)-a(27) added using data from Caldwell's page and A006880 by _Chai Wah Wu_, Apr 27 2018

%E a(28) obtained using A006880. - _Eduard Roure Perdices_, Apr 16 2021

%E a(29) obtained using A006880. - _Eduard Roure Perdices_, Dec 27 2022