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A057327
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First member of a prime quadruple in a 2p-1 progression.
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13
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1531, 2131, 2311, 3061, 6211, 6841, 7411, 10321, 13681, 15391, 16651, 18121, 22531, 23011, 24391, 29671, 30781, 31771, 33301, 35311, 41491, 44371, 46411, 54601, 56311, 57991, 60331, 61381, 66601, 67651, 78031, 83431, 85381, 88741
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OFFSET
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0,1
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COMMENTS
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Numbers n such that n remains prime through 3 iterations of function f(x) = 2x - 1.
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LINKS
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EXAMPLE
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Quadruplets are (1531,3061,6121,12241), (2131,4261,8521,17041), ...
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MATHEMATICA
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Select[Prime[Range[9000]], And@@PrimeQ[NestList[2#-1&, #, 3]]&] (* Harvey P. Dale, May 27 2012 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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