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URL: https://oeis.org/A140331

⇱ A140331 - OEIS

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A140331
Smallest k such that 3^(3^n) - k is prime.
4
1, 4, 2, 26, 10, 466, 506, 128, 13342, 5974, 8410, 6470
OFFSET
0,2
COMMENTS
This is to 3 as A058220 is to 2.
FORMULA
a(n) = A064722(A055777(n)). - Michel Marcus, Jan 28 2015
EXAMPLE
a(4) = 10 because 3^(3^4) - 10 = 443426488243037769948249630619149892793 is prime.
PROG
(PARI) a(n) = x = 3^(3^n); x - precprime(x); \\ Michel Marcus, Jan 28 2015
CROSSREFS
Cf. A055777 (3^(3^n)), A058220.
Sequence in context: A228474 A058167 A372849 * A095896 A286798 A123670
KEYWORD
more,nonn
AUTHOR
Jonathan Vos Post, May 26 2008
EXTENSIONS
a(5)-a(8) from Cino Hilliard, Jun 02 2008
a(9)-a(10) from Donovan Johnson, Sep 13 2008
a(0) prepended and a(11) from Michael S. Branicky, Aug 23 2024
STATUS
approved