A160503 Least prime divisor of pi(10^n).

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, 2, 3

Offset

1,1

Links

Table of n, a(n) for n=1..29.

C. Caldwell's Prime Pages, A Table of values of pi(x).

Formula

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

Example

a(1)=2 because under 10^1 there are 4 primes, and least prime divisor = 2.
a(4)=1229 because under 10^4 there are 1229 primes and that number, being prime, is its own least prime divisor.

Crossrefs

Cf. A006880, A141306.

Sequence in context: A170908 A229029 A055385 * A108429 A130280 A160127

Adjacent sequences: A160500 A160501 A160502 * A160504 A160505 A160506

Keyword

nonn,more

Author

Enoch Haga, May 16 2009

Extensions

Edited by Ray Chandler, May 20 2009

a(24)-a(27) added using data from Caldwell's page and A006880 by Chai Wah Wu, Apr 27 2018

a(28) obtained using A006880. - Eduard Roure Perdices, Apr 16 2021

a(29) obtained using A006880. - Eduard Roure Perdices, Dec 27 2022

Status

approved