A171249 - OEIS

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A171249

Numbers k such that 10^k*(2+3*10^k)+3 is prime.

%I #8 Jun 23 2023 10:52:23

%S 2,3,4,6,7,25,38,152,312,824,1195,1211,1335,2228,3435,3787,10317,

%T 11140,11239

%N Numbers k such that 10^k*(2+3*10^k)+3 is prime.

%C No more terms up to k = 3800.

%o (PARI) is(n)=ispseudoprime(10^n*(2+3*10^n)+3) \\ _Charles R Greathouse IV_, Jun 13 2017

%K more,nonn

%O 1,1

%A _Jason Earls_, Dec 06 2009

%E a(17)-a(19) from _Michael S. Branicky_, Jun 22 2023