A173852 Primes of the form 10^n - 2^n - 1.

7, 991, 999999487, 999999999967231

Offset

1,1

Comments

The next term is too large to display here.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..6

Mathematica

Select[Table[10^n-2^n-1, {n, 0, 100}], PrimeQ] (* Vincenzo Librandi, Jul 26 2012 *)

Prog

(Magma) /* The code gives only the terms up to a(5): */ [a: n in [0..200] | IsPrime(a) where a is 10^n-2^n-1]; // Vincenzo Librandi, Jul 26 2012

Crossrefs

Cf. A174179.

Sequence in context: A201070 A332197 A213960 * A062841 A349736 A110718

Adjacent sequences: A173849 A173850 A173851 * A173853 A173854 A173855

Keyword

nonn,hard

Author

Vincenzo Librandi, Feb 26 2010

Status

approved