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A356826
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Numbers k such that 2^k - 29 is prime.
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11
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OFFSET
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1,1
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COMMENTS
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A particularly low-density pseudo-Mersenne sequence. I have verified that there are no additional terms for k < 5*10^4. For k = a(5), a(6), a(7), and a(8), 2^k - 29 is a probable prime (see link).
The terms a(5)-a(8) were discovered by Henri Lifchitz (see link). - Elmo R. Oliveira, Nov 29 2023
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LINKS
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EXAMPLE
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5 is a term because 2^5 - 29 = 3 is prime.
8 is a term because 2^8 - 29 = 227 is prime.
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PROG
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(PARI) for(n=2, 1000, if(isprime(2^n-29), print1(n, ", ")))
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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), A059608 (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), this sequence (d=29).
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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