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A096650
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Indices of prime Pell numbers.
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14
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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
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1,1
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COMMENTS
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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
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LINKS
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EXAMPLE
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P(11)=5741, which is prime.
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MAPLE
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Pell:= gfun:-rectoproc( {a(0) = 0, a(1) = 1, a(n) = 2*a(n-1) + a(n-2)}, a(n), remember):
select(t -> isprime(t) and isprime(Pell(t)), [2, seq(2*i+1, i=1..2000)]); # Robert Israel, Aug 28 2015
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MATHEMATICA
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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 *)
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CROSSREFS
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KEYWORD
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nonn,hard,more
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AUTHOR
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Julien Peter Benney (jpbenney(AT)ftml.net), Aug 15 2004
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EXTENSIONS
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STATUS
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approved
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