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A091642 Number of primes less than 10^n which do not contain the digit 8. 10
4, 23, 141, 915, 6375, 46799, 355805, 2774348, 22023132, 177273427, 1443074791, 11855541525, 98146301284, 817786989282 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Number of primes less than 10^n after removing any primes with at least one digit 8.

a(n) = A006880(n) - A091709(n).

EXAMPLE

a(2) = 23 because of the 25 primes less than 10^2, 2 have at least one digit 8; 25-2 = 23.

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], 8] == {}, c++ ]]; Print[c]; p--, {n, 1, 8}] (* Robert G. Wilson v, Feb 02 2004 *)

CROSSREFS

Cf. A091634, A091635, A091636, A091637, A091638, A091639, A091640, A091641, A091643.

Sequence in context: A290052 A158197 A038736 * A162561 A277921 A020079

Adjacent sequences:  A091639 A091640 A091641 * A091643 A091644 A091645

KEYWORD

more,nonn,base

AUTHOR

Enoch Haga, Jan 30 2004

EXTENSIONS

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

a(9)-a(12) from Donovan Johnson, Feb 14 2008

a(13) from Robert Price, Nov 08 2013

a(14) from Giovanni Resta, Mar 20 2017

STATUS

approved

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Last modified March 22 17:25 EDT 2019. Contains 321422 sequences. (Running on oeis4.)