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A269835
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Primes p of the form 2^k + 4*(-1)^k - 3.
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1
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OFFSET
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1,1
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COMMENTS
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a(7) has 216 digits (see b-file).
Fermat primes > 3 from A019434 are terms.
Corresponding values of k: 0, 2, 4, 8, 16, 39, 715, ....
Note that for k = 1, 2^k + 4*(-1)^k - 3 = -5.
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LINKS
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MATHEMATICA
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Select[Table[2^k+4(-1)^k-3, {k, 0, 50}], Positive[#]&&PrimeQ[#]&] (* Harvey P. Dale, Sep 14 2019 *)
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PROG
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(Magma) [2] cat [2^k + 4*(-1)^k - 3: k in [2..300] | IsPrime(2^k + 4*(-1)^k - 3)]
(PARI) for (k=0, 40, my(j=2^k+4*(-1)^k-3); if(isprime(j), print1(j, ", "))) \\ Hugo Pfoertner, Nov 21 2019
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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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