A173839 Primes of the form 10^n - 2*n - 1.

7, 99989, 99999999977, 99999999999971, 9999999999999999961, 9999999999999999999999999999999999999999999999999999889, 99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999797

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..9

Mathematica

 Select[Table[10^n - 2*n - 1, {n, 0, 200}], PrimeQ] (* Vincenzo Librandi, Dec 01 2012 *)

Prog

(Magma) [a: n in [0..200] | IsPrime(a) where a is 10^n - 2*n - 1]; // Vincenzo Librandi, Dec 01 2012

Crossrefs

Cf. A174177.

Sequence in context: A110719 A068162 A158816 * A122000 A291906 A090769

Adjacent sequences: A173836 A173837 A173838 * A173840 A173841 A173842

Keyword

nonn

Author

Vincenzo Librandi, Feb 26 2010

Status

approved