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A096210 Primes of the form 10^n + 10^(n-2) - 1. 1
1009, 10099, 100999, 1009999999, 100999999999, 100999999999999999999999, 100999999999999999999999999999999999999, 100999999999999999999999999999999999999999 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..11

MATHEMATICA

t={}; Do[m=n; p=10^n+10^(n-2)-1; If[PrimeQ[p], AppendTo[t, p]], {n, 300}]; t (* Vincenzo Librandi, Jul 17 2012 *)

Select[Table[10^n+10^(n-2)-1, {n, 50}], PrimeQ] (* Harvey P. Dale, Apr 13 2019 *)

PROG

(PARI) f(n, z) = for(x=z, n, y=10^x+10^(x-z)-1; if(ispseudoprime(y), print1(y", ")))

CROSSREFS

Sequence in context: A308793 A180088 A117359 * A133584 A139059 A123156

Adjacent sequences:  A096207 A096208 A096209 * A096211 A096212 A096213

KEYWORD

nonn

AUTHOR

Cino Hilliard, Jul 28 2004

STATUS

approved

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Last modified June 20 12:04 EDT 2021. Contains 345164 sequences. (Running on oeis4.)