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A156895
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Primes of the form 1 + Product_{j=0..k} (2^j + 1).
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0
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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(2^0 + 1)*(2^1 + 1)*(2^2 + 1)*(2^3 + 1)*(2^4 + 1) + 1 = 2*3*5*9*17 + 1 = 4591.
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MAPLE
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a := proc (n) if isprime(1+product(2^k+1, k = 0 .. n)) = true then 1+product(2^k+1, k = 0 .. n) else end if end proc: seq(a(n), n = 0 .. 40); # Emeric Deutsch, Mar 07 2009
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MATHEMATICA
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Select[Table[Product[2^j+1, {j, 0, k}], {k, 0, 30}]+1, PrimeQ] (* Harvey P. Dale, Aug 01 2019 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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