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Search: id:A144487
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A144487 Primes of the form 2^(n+1)+15. +0
2
17, 19, 23, 31, 47, 79, 271, 1039, 2063, 4111, 32783, 65551, 4194319, 8388623, 67108879, 1073741839, 4294967311, 1099511627791, 4398046511119, 70368744177679, 2305843009213693967, 4722366482869645213711 (list; graph; listen)
OFFSET

1,1

COMMENT

Conjecture: Let n>=0 If 2^n+6 =/=[(p^2-3)/2] mod (p) then 2^(n+1)+15=p (prime number) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Feb 21 2009]

PROGRAM

(PARI) {for(n=0, 72, if(isprime(k=2^n+15), print1(k, ", ")))}

CROSSREFS

Cf. A057197 (numbers n such that 2^n + 15 is prime). [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Dec 11 2008]

Sequence in context: A106932 A007635 A140947 this_sequence A108266 A102325 A038711

Adjacent sequences: A144484 A144485 A144486 this_sequence A144488 A144489 A144490

KEYWORD

nonn

AUTHOR

Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Dec 09 2008

EXTENSIONS

Edited by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Dec 10 2008

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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.


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