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A178995
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Numbers k such that 3^k (mod 2^k) is prime.
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1
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3, 5, 7, 9, 11, 20, 28, 62, 161, 204, 471, 505, 881, 1810, 1812, 2506, 3321, 6809, 9272, 15131, 17449, 25250, 27989, 36082, 53309, 64970, 66354, 69646
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OFFSET
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1,1
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LINKS
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FORMULA
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MATHEMATICA
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fQ[n_] := PrimeQ@ PowerMod[3, n, 2^n]; k = 1; lst = {}; While[k < 15001, If[fQ@ k, AppendTo[lst, k]]; k++]; lst
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PROG
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(PARI) for(n=1, 10^5, if(ispseudoprime((3^n)%(2^n)), print1(n, ", "))) \\ Felix Fröhlich, Jun 05 2014
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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