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A228145
Numbers k such that 2*Fibonacci(k) - 1 is prime.
2
3, 4, 8, 9, 10, 16, 18, 31, 34, 39, 41, 42, 55, 68, 79, 90, 95, 97, 114, 122, 148, 151, 160, 209, 265, 320, 329, 441, 457, 516, 529, 632, 640, 682, 712, 791, 1056, 1169, 1632, 1943, 2200, 2279, 2468, 2698, 2921, 2996, 3129, 3140, 3656, 3960, 4889, 5560, 5895
OFFSET
1,1
LINKS
Jorge Coveiro, Table of n, a(n) for n = 1..62 (first 55 terms from Vincenzo Librandi)
MATHEMATICA
Select[Range[2000], PrimeQ[2 Fibonacci[#] - 1]&]
PROG
(Magma) [n: n in [1..1700] | IsPrime(2*Fibonacci(n)-1)];
(PARI) is(n)=ispseudoprime(2*fibonacci(n)-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A342791 A275096 A109826 * A243064 A057549 A284392
KEYWORD
nonn
AUTHOR
Vincenzo Librandi, Aug 13 2013
STATUS
approved