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Search: id:A074173
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| A074173 |
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Numbers n such that n and n+2 are of the form p^2*q where p and q are primes. |
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3
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| 18, 50, 242, 423, 475, 603, 637, 722, 845, 925, 1682, 1773, 2007, 2523, 2525, 2527, 3175, 3177, 4203, 4475, 4525, 4923, 5823, 6725, 6811, 6962, 7299, 7442, 7675, 8425, 8957, 8973, 9457, 9925, 10051, 10082, 10467, 11673, 11709, 12427, 12482, 12591
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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18 is a member as 18 = 3^2*2 and 20 = 2^2*5.
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MATHEMATICA
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lst={}; Do[f1=FactorInteger[n]; If[Sort[Transpose[f1][[2]]]=={1, 2}, f2=FactorInteger[n+2]; If[Sort[Transpose[f2][[2]]]=={1, 2}, AppendTo[lst, n]]], {n, 3, 10000}]; lst
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CROSSREFS
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Cf. A074172, A074174, A054753.
Sequence in context: A102835 A095990 A102836 this_sequence A092068 A093520 A051870
Adjacent sequences: A074170 A074171 A074172 this_sequence A074174 A074175 A074176
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KEYWORD
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nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Aug 30 2002
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EXTENSIONS
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More terms from T. D. Noe (noe(AT)sspectra.com), Oct 04 2004
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