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%I #14 Sep 08 2022 08:45:17
%S 1,7,31,37,39,49,57,61,63,67,81,93,99,111,117,159,171,177,181,199,211,
%T 231,241,243,273,289,307,309,337,349,369,397,439,441,447,483,489,493,
%U 513,519,523,537,541,553,559,577,591,601,607,621,661,663,673,679,699
%N Numbers n such that the string 235n is the decimal expansion of a prime number.
%H Robert Israel, <a href="/A103630/b103630.txt">Table of n, a(n) for n = 1..10000</a>
%e 1 is in the sequence because 2351 is prime.
%e 49 is in the sequence because 23549 is prime.
%e 171 is in the sequence because 235171 is prime.
%p map(p->p[2],select(p -> isprime(235*10^p[1]+p[2]), [seq([1,k],k=1..9,2),seq(seq([d,k],k=10^(d-1)+1..10^d,2),d=2..3)])); # _Robert Israel_, Jan 11 2018
%o (Magma) [ n: n in [1..800] | IsPrime(Seqint(Intseq(n) cat [5, 3, 2])) ]; // Klaus Brockhaus, Feb 02 2011
%K base,nonn
%O 1,2
%A _Parthasarathy Nambi_, Mar 25 2005
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