

A096650


Indices of prime Pell numbers.


14



2, 3, 5, 11, 13, 29, 41, 53, 59, 89, 97, 101, 167, 181, 191, 523, 929, 1217, 1301, 1361, 2087, 2273, 2393, 8093, 13339, 14033, 23747, 28183, 34429, 36749, 90197
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OFFSET

1,1


COMMENTS

For a Pell number to be prime, the index must be prime. The indices greater than 523 yield probable primes. No others less than 100000.  T. D. Noe, Sep 13 2004
n divides m if and only if A000129(n) divides A000129(m). This is the reason of the fact that this sequence is a subsequence of A000040. For complement of this sequence see A270387.  Altug Alkan, Apr 29 2016


LINKS



EXAMPLE

P(11)=5741, which is prime.


MAPLE

Pell:= gfun:rectoproc( {a(0) = 0, a(1) = 1, a(n) = 2*a(n1) + a(n2)}, a(n), remember):
select(t > isprime(t) and isprime(Pell(t)), [2, seq(2*i+1, i=1..2000)]); # Robert Israel, Aug 28 2015


MATHEMATICA

lst={}; a=0; b=1; Do[c=a+2b; a=b; b=c; If[PrimeQ[c], AppendTo[lst, n]], {n, 2, 10000}]; lst (* T. D. Noe, Aug 17 2004 *)


CROSSREFS



KEYWORD

nonn,hard,more


AUTHOR

Julien Peter Benney (jpbenney(AT)ftml.net), Aug 15 2004


EXTENSIONS



STATUS

approved



