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Search: id:A157352
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| A157352 |
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Products (semiprimes) of two distinct safe primes. |
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+0
7
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| 35, 55, 77, 115, 161, 235, 253, 295, 329, 413, 415, 517, 535, 581, 649, 749, 835, 895, 913, 1081, 1135, 1169, 1177, 1253, 1315, 1357, 1589, 1735, 1795, 1837, 1841, 1909, 1915, 1969, 2335, 2395, 2429, 2461, 2497, 2513, 2515, 2681, 2773, 2815, 2893, 2935
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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35=5*7; 5 and 7 are safe primes, 55=5*11; 5 and 11 are safe primes,...
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MATHEMATICA
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lst={}; Do[If[Plus@@Last/@FactorInteger[n]==2, a=Length[First/@FactorInteger[n]]; If[a==2, b=First/@FactorInteger[n]; c=b[[1]]; d=b[[2]]; If[PrimeQ[(c-1)/2]&&PrimeQ[(d-1)/2], AppendTo[lst, n]]]], {n, 7!}]; lst
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CROSSREFS
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Cf. A001358, A005384, A005385, A006881, A007304, A111206, A157342, A157344, A157345, A157346, A157347
Sequence in context: A039312 A043915 A121707 this_sequence A090877 A048033 A078819
Adjacent sequences: A157349 A157350 A157351 this_sequence A157353 A157354 A157355
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KEYWORD
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nonn
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AUTHOR
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Vladimir Orlovsky (4vladimir(AT)gmail.com), Feb 27 2009
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