A229661 Rounded percentage of primes less than 10^n.

0, 40, 25, 17, 12, 10, 8, 7, 6, 5, 5, 4, 4, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2

Offset: 0

Author

Jean-François Alcover, Sep 27 2013

Keywords

• nonn
• base
• hard
• less

Comments

Please refer to the explanations and comments given in A006879 and A006880.

Examples

			There are 4 primes less than 10 (i.e., 2, 3, 5, 7), so a(1) = 40.
		

Crossrefs

Cf. A000720, A006879, A006880, A007053, A040014, A006988.

Programs

Mathematica

a[n_] := PrimePi[10^n]/10^(n-2) // Round;
(* or *) a[n_] := A006880[[n+1]]/10^(n-2) // Round; Table[Print["10^", n, " ", a[n], "%"]; a[n], {n, 0, 25}] (* Jean-François Alcover, Sep 27 2013 *)

Formula

a(n) = pi(10^n)/10^(n-2) rounded.