%I
%S 7,991,999999487,999999999967231
%N Primes of the form 10^n  2^n  1.
%C The next term is too large to display here.
%H Vincenzo Librandi, <a href="/A173852/b173852.txt">Table of n, a(n) for n = 1..6</a>
%t Select[Table[10^n2^n1,{n,0,100}],PrimeQ] (* _Vincenzo Librandi_, Jul 26 2012 *)
%o (MAGMA) /* The code gives only the terms up to a(5): */ [a: n in [0..200]  IsPrime(a) where a is 10^n2^n1]; // _Vincenzo Librandi_, Jul 26 2012
%Y Cf. A174179.
%K nonn,hard
%O 1,1
%A _Vincenzo Librandi_, Feb 26 2010
