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%I #24 Jun 01 2023 02:46:17
%S 1,2,4,5,6,7,14,21,27,34,53,72,96,145,168,191,192,309,393,502,667,
%T 1055,1534,1710,4171,4838,4950,9932,10860,11906,14148,17184,27054,
%U 31435
%N Numbers k such that (35*10^k - 11)/3 is prime.
%C Numbers k such that digits 11 followed by k-1 occurrences of digit 6 followed by digit 3 is prime. E.g., 116666...666663.
%C a(35) > 3*10^5. - _Robert Price_, Oct 16 2015
%H Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/primedifficulty.txt">Search for 116w3.</a>
%e 7 is in this sequence because (35*10^7 - 11)/3 = 116666663 is prime.
%t Select[Range[0, 100000], PrimeQ[(35*10^# - 11)/3] &]
%o (Magma) [n: n in [0..400] |IsPrime((35*10^n-11) div 3)]; // _Vincenzo Librandi_, Feb 05 2016
%o (PARI) lista(nn) = {for(n=1, nn, if(ispseudoprime((35*10^n-11)/3), print1(n, ", ")));} \\ _Altug Alkan_, Feb 05 2016
%Y Cf. A056654.
%K more,nonn
%O 1,2
%A _Robert Price_, Feb 04 2016
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