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A230527
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Numbers n such that 3^6*2^n - 1 is prime.
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3
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5, 17, 23, 113, 125, 173, 199, 319, 377, 397, 785, 937, 2167, 3785, 3977, 5957, 7727, 8249, 14677, 19577, 20485, 36319, 57509, 60703, 66677, 76877, 77017, 83407, 229405, 1003373
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OFFSET
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1,1
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COMMENTS
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Riesel Primes with k = 3^6 = 729.
Checked up to n = 1003600.
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LINKS
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EXAMPLE
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729*2^5-1=23327 is a prime number.
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MATHEMATICA
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b=3^6; i=0; Table[While[i++; cp=b*2^i-1; !PrimeQ[cp]]; i, {j, 1, 15}]
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PROG
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CROSSREFS
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KEYWORD
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nonn,hard
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AUTHOR
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EXTENSIONS
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Lei Zhou, Nov 08 2013, added a Mathematica program for small elements.
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STATUS
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approved
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