A114056 - OEIS

%I #11 Apr 16 2023 04:15:54

%S 1,2,3,7,8,222,227,360,535,2713,9079

%N Numbers k such that 2^prime(k) - 1 + 10^k is prime.

%e 7 is there because the 7th prime is 17 and 2^17-1+10^7 is prime.

%t Position[PrimeQ[Table[(2^Prime[n] - 1) + 10^n, {n, 10}]], True]

%K nonn,more

%O 1,2

%A Joao Carlos Leandro da Silva (zxawyh66(AT)yahoo.com), Feb 02 2006

%E Edited by _Don Reble_, Jul 23 2006

%E a(10)-a(11) from _Michael S. Branicky_, Apr 15 2023