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A057326
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First member of a prime triple in a 2p-1 progression.
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23
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2, 19, 79, 331, 439, 499, 619, 829, 1069, 1279, 1531, 2089, 2131, 2179, 2311, 2791, 3019, 3061, 3109, 3181, 3769, 4159, 4231, 4261, 4621, 4639, 4861, 4951, 5419, 5749, 6121, 6211, 6709, 6841, 7369, 7411, 7561, 7639, 8209, 8629, 9109, 9199, 9319, 9739
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| Numbers n such that n remains prime through 2 iterations of function f(x) = 2x - 1.
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LINKS
| Index entries for sequences related to primes in arithmetic progressions
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EXAMPLE
| Triplets are (2,3,5),(19,37,73),(79,157,313),(331,661,1321),...
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MATHEMATICA
| Select[Prime[Range[1500]], And@@PrimeQ[NestList[2#-1&, #, 2]]&] (* From Harvey P. Dale, Dec 09 2011 *)
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CROSSREFS
| Cf. (A005382 and A005383), A057327, A057328, A057329, A057330, A005603.
Sequence in context: A024389 A110050 A054209 * A129446 A054570 A135436
Adjacent sequences: A057323 A057324 A057325 * A057327 A057328 A057329
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KEYWORD
| nonn
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AUTHOR
| Patrick De Geest (pdg(AT)worldofnumbers.com), Aug 15 2000.
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