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 A065582 Smallest prime ending in exactly n 9's. 11
 19, 199, 1999, 49999, 199999, 2999999, 19999999, 799999999, 10999999999, 59999999999, 1099999999999, 34999999999999, 59999999999999, 499999999999999, 14999999999999999, 139999999999999999 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Harry J. Smith, Table of n, a(n) for n = 1..100 MATHEMATICA Do[a = Table[9, {n} ]; k = 0; While[ b = FromDigits[ Join[ IntegerDigits[k], a]]; Mod[k, 10] == 9 || !PrimeQ[b], k++ ]; Print[b], {n, 1, 17} ] pe9[n_]:=Module[{k=1, rh=FromDigits[PadRight[{}, n, 9]]}, While[!PrimeQ[ k 10^n+rh], k++]; k 10^n+rh]; Array[pe9, 20] (* Harvey P. Dale, Mar 26 2012 *) PROG (PARI) { for (n=1, 100, t=10^n; b=t - 1; d=0; while(!isprime(b + t*d), d++; if (d%10==9, d++)); write("b065582.txt", n, " ", b + t*d) ) } \\ Harry J. Smith, Oct 23 2009 CROSSREFS Cf. A037071, A065592, A065821, A065580, A065581. Sequence in context: A135162 A185687 A067272 * A241021 A055558 A160452 Adjacent sequences:  A065579 A065580 A065581 * A065583 A065584 A065585 KEYWORD nonn,base AUTHOR Robert G. Wilson v, Nov 28 2001 STATUS approved

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Last modified February 19 13:17 EST 2020. Contains 332044 sequences. (Running on oeis4.)