A176987 Primes of the form 10^n-27.

73, 9973, 9999973, 99999999999973, 99999999999999999973, 9999999999999999999973, 99999999999999999999999999973, 9999999999999999999999999999973, 9999999999999999999999999999999999999973

Offset: 1

Author

Vincenzo Librandi, Dec 11 2010

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..14

Crossrefs

Cf. A108329.

Programs

Magma

[a: n in [2..250]|IsPrime(a) where a is 10^n-27];

Mathematica

Select[Table[10^n - 27, {n, 2, 500}], PrimeQ] (* Vincenzo Librandi, Jan 03 2014 *)
Select[Table[FromDigits[PadLeft[{7,3},n,9]],{n,2,40}],PrimeQ] (* Harvey P. Dale, Jul 08 2024 *)