A091647 Number of primes less than 10^n having at least one digit 3.

1, 9, 66, 561, 4877, 43685, 399564, 3694303, 34433999, 322852288, 3041362298, 28758431735, 272777483044, 2594081699837

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Example

a(2) = 9 because of the 25 primes less than 10^2, 9 have at least one digit 3.

Mathematica

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; c = 0; p = 1; Do[ While[ p = NextPrim[p]; p < 10^n, If[ Position[ IntegerDigits[p], 3] != {}, c++ ]]; Print[c]; p--, {n, 1, 8}] (* Robert G. Wilson v, Feb 02 2004 *)

Crossrefs

a(n) + A091637(n) = A006880(n).

Cf. A091637, A091644, A091645, A091646, A091705, A091706, A091707, A091708, A091709, A091710.

Sequence in context: A134432 A098107 A226201 * A321945 A232018 A231199

Adjacent sequences: A091644 A091645 A091646 * A091648 A091649 A091650

Keyword

nonn,base

Author

Enoch Haga, Jan 30 2004

Extensions

Edited and extended by Robert G. Wilson v, Feb 02 2004

3 more terms from Ryan Propper, Aug 20 2005

a(13) from Robert Price, Nov 11 2013

a(14) from Giovanni Resta, Jul 21 2015

Status

approved