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Search: id:A158338
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| A158338 |
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Composite numbers k such that k - number of divisors of k = prime. |
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+0
1
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| 6, 15, 16, 21, 27, 33, 35, 51, 57, 65, 77, 87, 93, 105, 111, 135, 141, 143, 155, 161, 165, 177, 183, 185, 189, 201, 203, 215, 231, 237, 245, 267, 275, 285, 287, 321, 335, 341
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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If composite=6(1, 2, 3, 6) and 6-4=2=prime, then 6=a(1). If composite=15(1, 3, 5, 15) and 15-4=11=prime, then 15=a(2). If composite=16(1, 2, 4, 8, 16) and 16-5=11=prime, then 16=a(3)etc.
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CROSSREFS
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Cf. A000040, A002808, A035004.
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KEYWORD
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nonn,new
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AUTHOR
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Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Mar 16 2009, Nov 14 2009
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