The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A091647 Number of primes less than 10^n having at least one digit 3. 10
 1, 9, 66, 561, 4877, 43685, 399564, 3694303, 34433999, 322852288, 3041362298, 28758431735, 272777483044, 2594081699837 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 21 21:32 EDT 2021. Contains 347605 sequences. (Running on oeis4.)