login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

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

%I #16 Jul 21 2015 06:06:35

%S 1,9,66,561,4877,43685,399564,3694303,34433999,322852288,3041362298,

%T 28758431735,272777483044,2594081699837

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

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

%t 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 *)

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

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

%K nonn,base

%O 1,2

%A _Enoch Haga_, Jan 30 2004

%E Edited and extended by _Robert G. Wilson v_, Feb 02 2004

%E 3 more terms from _Ryan Propper_, Aug 20 2005

%E a(13) from _Robert Price_, Nov 11 2013

%E a(14) from _Giovanni Resta_, Jul 21 2015