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A109069 Numbers n such that the string n2323 is prime. 1

%I

%S 1,3,4,6,12,19,22,25,43,48,52,54,57,63,66,67,70,73,82,84,85,87,111,

%T 132,139,145,150,151,157,159,160,172,175,187,195,201,204,210,211,213,

%U 216,217,223,228,235,238,241,256,258

%N Numbers n such that the string n2323 is prime.

%H Robert Israel, <a href="/A109069/b109069.txt">Table of n, a(n) for n = 1..10000</a>

%e n=1 is in the sequence because n2323 = 12323 is prime.

%e n=87 is in the sequence because n2323 = 872323 is prime.

%p select(t -> isprime(10^4*t+2323),[$1..1000]); # _Robert Israel_, Mar 05 2020

%K nonn,base

%O 1,2

%A _Parthasarathy Nambi_, Aug 17 2005

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Last modified September 27 22:36 EDT 2020. Contains 337388 sequences. (Running on oeis4.)