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A065592 Smallest prime beginning with exactly n 9's. 12
2, 97, 991, 99901, 99991, 9999901, 9999991, 999999929, 9999999929, 99999999907, 999999999937, 9999999999971, 99999999999923, 999999999999947, 9999999999999917, 99999999999999919, 99999999999999997 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

M. F. Hasler, Table of n, a(n) for n = 1..201

MATHEMATICA

fp[n_]:=Select[Join[10*n+{1, 7}, 100*n+Range[1, 99, 2]], PrimeQ, 1]; With[{ns=Table[FromDigits[PadRight[{}, n, 9]], {n, 20}]}, Join[{2}, Flatten[fp/@ns]]] (* Harvey P. Dale, May 12 2012 *)

CROSSREFS

Cf. A037071, A065582, A065584 - A065591.

Sequence in context: A189313 A042151 A233192 * A233767 A223936 A224083

Adjacent sequences:  A065589 A065590 A065591 * A065593 A065594 A065595

KEYWORD

nonn,base

AUTHOR

Robert G. Wilson v, Nov 28 2001

EXTENSIONS

Corrected by Don Reble, Jan 17 2007

STATUS

approved

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Last modified December 12 20:12 EST 2019. Contains 329961 sequences. (Running on oeis4.)