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A234696
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Indices of primes in the tribonacci-like sequence, A214727.
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18
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1, 2, 3, 8, 16, 20, 64, 208, 364, 2652, 7763, 17280, 24104, 31823, 70864, 74008
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OFFSET
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1,2
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COMMENTS
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a(17) > 2*10^5.
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LINKS
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MATHEMATICA
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a={1, 2, 2}; Print[2]; Print[2]; For[n=3, n<=1000, n++, sum=Plus@@a; If[PrimeQ[sum], Print[n]]; a=RotateLeft[a]; a[[3]]=sum]
Position[LinearRecurrence[{1, 1, 1}, {1, 2, 2}, 75000], _?PrimeQ]-1//Flatten (* Harvey P. Dale, Sep 02 2016 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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