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%I #12 Apr 06 2022 11:31:06
%S 13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,113,199,
%T 211,223,227,229,233,277,311,331,337,433,443,449,499,557,577,599,661,
%U 677,733,773,811,877,881,883,887,911,977,991,997,1117,1777,1999,2111
%N Primes of the form iii...ijjj...j, i != j.
%H Sean A. Irvine, <a href="/A034845/b034845.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Union[Flatten[Table[FromDigits[Join[PadRight[{},n,m],PadRight[{},k,q]]],{n,3},{m,9},{k,3},{q,{1,3,7,9}}]]],IntegerDigits[#][[1]]!=IntegerDigits[#][[-1]]&&PrimeQ[#]&] (* _Harvey P. Dale_, Apr 06 2022 *)
%Y Cf. A235154.
%K nonn,base
%O 1,1
%A _Erich Friedman_
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