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 A268448 Numbers n such that (35*10^n - 11)/3 is prime. 505
 1, 2, 4, 5, 6, 7, 14, 21, 27, 34, 53, 72, 96, 145, 168, 191, 192, 309, 393, 502, 667, 1055, 1534, 1710, 4171, 4838, 4950, 9932, 10860, 11906, 14148, 17184, 27054, 31435 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Numbers n such that digits 11 followed by n-1 occurrences of digit 6 followed by digit 3 is prime. E.g., 116666...666663. a(35) > 10^5. - Robert Price, Oct 16 2015 LINKS Makoto Kamada, Search for 116w3. EXAMPLE 7 is in this sequence because (35*10^7 - 11)/3 = 116666663 is prime. MATHEMATICA Select[Range[0, 100000], PrimeQ[(35*10^# - 11)/3] &] PROG (MAGMA) [n: n in [0..400] |IsPrime((35*10^n-11) div 3)]; // Vincenzo Librandi, Feb 05 2016 (PARI) lista(nn) = {for(n=1, nn, if(ispseudoprime((35*10^n-11)/3), print1(n, ", "))); } \\ Altug Alkan, Feb 05 2016 CROSSREFS Cf. A056654. Sequence in context: A092058 A134532 A282278 * A230581 A248962 A323455 Adjacent sequences:  A268445 A268446 A268447 * A268449 A268450 A268451 KEYWORD more,nonn AUTHOR Robert Price, Feb 04 2016 STATUS approved

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Last modified February 26 12:43 EST 2020. Contains 332280 sequences. (Running on oeis4.)