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Search: id:A129401
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| A129401 |
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Each composite number n in turn is factored, each prime factor is replaced by the next prime, and then is remultiplied. |
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+0 1
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| 9, 15, 27, 25, 21, 45, 33, 35, 81, 75, 63, 55, 39, 135, 49, 51, 125, 99, 105, 243, 65, 57, 77, 225, 69, 85, 189, 165, 117, 175, 87, 405, 121, 147, 95, 153, 375, 91, 297, 115, 93, 315, 111, 275, 729, 119, 195, 171, 145, 231, 675, 123, 245, 207, 143, 255, 567, 625
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Each odd composite number appears in the sequence exactly once. - Jon E. Schoenfield (jonscho(AT)hiwaay.net), Jun 05 2007
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FORMULA
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Equals A003961(n) where n runs through the composite numbers. - Jon Schoenfield, Jun 04 2007
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EXAMPLE
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a(19) = 105 because the factorization of the 19th composite number (i.e., 30) is 2*3*5, and replacing each prime factor with the next prime results in 3*5*7 which remultiplies to 105.
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CROSSREFS
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Cf. A002808, A003961.
Adjacent sequences: A129398 A129399 A129400 this_sequence A129402 A129403 A129404
Sequence in context: A014003 A082549 A013569 this_sequence A046353 A046356 A060874
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KEYWORD
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nonn
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AUTHOR
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Ben Thurston (benthurston27(AT)yahoo.com), May 28 2007
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EXTENSIONS
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More terms from Jon E. Schoenfield (jonscho(AT)hiwaay.net), Jun 05 2007
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