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A020472 Primes that contain digits 8 and 9 only. 32
89, 8999, 89899, 89989, 98899, 98999, 99989, 888989, 898889, 989999, 998989, 8888989, 8889889, 8988989, 8989999, 8998889, 8999899, 9888889, 9889889, 9899999, 9989899, 9999889, 88888999, 88898989, 88989899, 89888989, 89889889, 89898889 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Or, primes with minimal digit 8.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index to entries about primes with digits in a given set

MATHEMATICA

Select[Prime[Range[80000]], Min[IntegerDigits[ # ]]==8&] - Zak Seidov, May 07 2005

Flatten[Table[Select[FromDigits/@Tuples[{8, 9}, n], PrimeQ], {n, 8}]] (* Vincenzo Librandi, Jul 27 2012 *)

PROG

(PARI) for(nd=1, 9, p=vector(nd, i, 10^(nd-i))~; forvec(v=vector(nd, i, [8+(i==nd), 9]), isprime(v*p) && print1(v*p", "))) \\ M. F. Hasler, Mar 18 2010

CROSSREFS

Cf. A020449 (digits 0 & 1), ..., A020471 (digits 7 & 9). [From M. F. Hasler, Mar 18 2010]

Sequence in context: A100419 A264135 A264020 * A263431 A093948 A116254

Adjacent sequences:  A020469 A020470 A020471 * A020473 A020474 A020475

KEYWORD

nonn,base

AUTHOR

David W. Wilson

EXTENSIONS

Edited by N. J. A. Sloane, Jan 26 2008 at the suggestion of Lekraj Beedasy

STATUS

approved

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Last modified February 19 20:48 EST 2018. Contains 299357 sequences. (Running on oeis4.)