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A125856 a(n) = least number k such that k^(2^n)+1, k^(2^n)+3, k^(2^n)+7 and k^(2^n)+9 are all prime. +0
1
4, 2, 83270, 5241160, 57171410, 359829200 (list; graph; listen)
OFFSET

0,1

COMMENT

In 1958, Schinzel showed that for each n>0, there are infinitely many primes among the numbers k^(2^n)+{1,3,7, or 9}.

REFERENCES

Sierpinski, W. Elementary theory of numbers. Warszawa 1964 Monografie Matematyczne Vol. 42.

CROSSREFS

Cf. A125855, A057015, A125779, A125780.

Sequence in context: A016518 A118202 A089331 this_sequence A057110 A073275 A030120

Adjacent sequences: A125853 A125854 A125855 this_sequence A125857 A125858 A125859

KEYWORD

nonn

AUTHOR

Artur Jasinski (grafix(AT)csl.pl), Dec 12 2006

EXTENSIONS

Edited by Don Reble (djr(AT)nk.ca), Dec 16 2006

One more term from Farideh Firoozbakht (mymontain(AT)yahoo.com), Jan 01 2007

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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