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A059608
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Numbers k such that 2^k - 5 is prime.
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25
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3, 4, 6, 8, 10, 12, 18, 20, 26, 32, 36, 56, 66, 118, 130, 150, 166, 206, 226, 550, 706, 810, 1136, 1228, 1818, 2368, 2400, 3128, 4532, 5112, 8492, 16028, 16386, 17392, 18582, 21986, 24292, 27618, 30918, 32762, 48212, 120440, 183632, 316140, 364982, 414032, 533350, 595122
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OFFSET
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1,1
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COMMENTS
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Except 3, all terms are even since for odd k, 2^k - 5 is divisible by 3.
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LINKS
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Henri Lifchitz and Renaud Lifchitz (Editors), Search for 2^n-5, PRP Top Records.
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EXAMPLE
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k = 10: 2^10 - 5 = 1019 is prime.
k = 20: 2^20 - 5 = 1048571 is prime.
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MATHEMATICA
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PROG
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CROSSREFS
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Cf. Sequences of numbers k such that 2^k - d is prime: A000043 (d=1), A050414 (d=3), this sequence (d=5), A059609 (d=7), A059610 (d=9), A096817 (d=11), A096818 (d=13), A059612 (d=15), A059611 (d=17), A096819 (d=19), A096820 (d=21), A057220 (d=23), A356826 (d=29).
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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