%I #7 Nov 18 2018 00:53:50
%S 2,9,27,6561,39135393,1291467969,3404825447,248155780267521,
%T 8422942255954625293713,717897987691852588770249
%N Least n-th power such that every concatenation is a prime.
%e 2, 29, 2927, etc. are primes.
%t c = ""; Do[k = 1; While[ !PrimeQ[ToExpression[c <> ToString[k^n]]], k++ ]; Print[k^n]; c = c <> ToString[k^n], {n, 1, 10}] (* _Ryan Propper_, Jul 08 2005 *)
%K base,nonn
%O 1,1
%A _Amarnath Murthy_, Dec 11 2003
%E More terms from _Ryan Propper_, Jul 08 2005