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A268448
Numbers k such that (35*10^k - 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
OFFSET
1,2
COMMENTS
Numbers k such that digits 11 followed by k-1 occurrences of digit 6 followed by digit 3 is prime. E.g., 116666...666663.
a(35) > 3*10^5. - Robert Price, Oct 16 2015
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 A361825 A248962
KEYWORD
more,nonn
AUTHOR
Robert Price, Feb 04 2016
STATUS
approved