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

0,2

Comments

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

Links

Table of n, a(n) for n=0..25.

Formula

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

Example

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

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 *)

Crossrefs

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

Sequence in context: A097208 A216137 A163956 * A070724 A035878 A022996

Adjacent sequences: A229658 A229659 A229660 * A229662 A229663 A229664

Keyword

nonn,base,hard,less

Author

Jean-François Alcover, Sep 27 2013

Status

approved