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A058221 Next-to-smallest k such that 2^(2^n) - k is prime. 1
2, 5, 15, 17, 17, 83, 173, 357, 629, 179, 2543, 8067, 5619, 29027, 38783, 99267 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
PROG
(PARI) a(n) = my(N = 2^(2^n)); N - precprime(precprime(N)-1) \\ Michel Marcus, Jun 29 2013
CROSSREFS
Cf. A058220.
Sequence in context: A146109 A146108 A032841 * A349734 A146122 A263457
KEYWORD
nonn,hard,more
AUTHOR
Warren D. Smith, Nov 30 2000
EXTENSIONS
a(15) from Jinyuan Wang, Jun 06 2020
a(16) from Michael S. Branicky, Apr 23 2023
STATUS
approved

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Last modified May 21 00:58 EDT 2024. Contains 372720 sequences. (Running on oeis4.)