OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..14
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 *)
PROG
(Magma) [a: n in [2..250]|IsPrime(a) where a is 10^n-27];
CROSSREFS
KEYWORD
nonn
AUTHOR
Vincenzo Librandi, Dec 11 2010
STATUS
approved