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A162712 Primes p such that 3^p-2^p-2 is also prime. 1
2, 3, 43, 61, 5563, 10093 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

The associated 3^p-2^p-2 are in A162713.

The list of k such that 3^k-2^k-2 is prime is k=2, 3, 43, 61, 63, 1369,... where 63 and 1369 are not prime.

Contribution from Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 03 2009: (Start)

No other term <=15000.

(End)

EXAMPLE

p=2 is in the sequence because 3^2-2^2-2=3 is prime. p=3 is in the sequence because 3^3-2^3-2=17 is prime.

MAPLE

a := proc (n) if isprime(n) = true and isprime(3^n-2^n-2) = true then n else end if end proc: seq(a(n), n = 1 .. 15000); [From Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 03 2009]

CROSSREFS

Cf. A162713.

Sequence in context: A087571 A126018 A051099 * A062581 A077520 A100015

Adjacent sequences:  A162709 A162710 A162711 * A162713 A162714 A162715

KEYWORD

nonn

AUTHOR

Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Jul 11 2009

EXTENSIONS

Edited by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 26 2009

a(5) and a(6) from Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 03 2009

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Last modified February 15 23:53 EST 2012. Contains 205860 sequences.