A096210 Primes of the form 10^n + 10^(n-2) - 1.

1009, 10099, 100999, 1009999999, 100999999999, 100999999999999999999999, 100999999999999999999999999999999999999, 100999999999999999999999999999999999999999

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