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 A020472 Primes that contain digits 8 and 9 only. 35
 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, 89999999, 98888989 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Or, primes with minimal digit 8. LINKS Michael S. Branicky, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Vincenzo Librandi) 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 (Python) from sympy import isprime from itertools import count, islice, product def agen(): # generator of terms for d in count(2): for first in product("89", repeat=d-1): t = int("".join(first) + "9") if isprime(t): yield t print(list(islice(agen(), 30))) # Michael S. Branicky, Nov 15 2022 CROSSREFS Cf. A020449 (digits 0 & 1), ..., A020471 (digits 7 & 9). - M. F. Hasler, Mar 18 2010 Sequence in context: A328355 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 Beedassy STATUS approved

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Last modified June 2 13:38 EDT 2023. Contains 363097 sequences. (Running on oeis4.)