A290864 - OEIS

A290864

Numbers k such that the k-th Fibonacci polynomial evaluated at k is prime.

2, 5, 71, 8419

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OFFSET

1,1

COMMENTS

Numbers k such that A084844(k) = A117715(k,k) is prime.

a(5) > 9200. - Giovanni Resta, Aug 13 2017

Except for a(1), all terms == 1 or 5 (mod 6). - Robert Israel, Aug 13 2017

LINKS

Eric Weisstein's World of Mathematics, Fibonacci Polynomial

EXAMPLE

5 is in the sequence because A117715(5,5) = 701 is prime.

MAPLE

select(t -> isprime(combinat:-fibonacci(t, t)), [2, seq(seq(6*i+j, j=[1, 5]), i=0..100)]); # Robert Israel, Aug 13 2017

MATHEMATICA

Select[Range[100], PrimeQ@ Fibonacci[#, #] ]&] (* Giovanni Resta, Aug 13 2017 *)

CROSSREFS

KEYWORD

nonn,more

AUTHOR

Bobby Jacobs, Aug 12 2017

EXTENSIONS

a(4) from Giovanni Resta, Aug 13 2017

STATUS

approved