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Search: id:A154370
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| A154370 |
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Numbers n such that largest prime factor of composite(n) - smallest prime factor of composite(n) = prime. |
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+0
1
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| 5, 7, 8, 11, 16, 18, 19, 23, 25, 27, 28, 34, 36, 39, 42, 50, 53, 54, 56, 57, 60, 62, 65, 72, 74, 76, 82, 83, 89, 91, 93, 95, 98, 100, 102, 105, 108, 111, 114, 115, 119, 122, 128, 132, 133, 138, 139, 143, 147, 151, 153, 159, 161, 163
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OFFSET
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1,1
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EXAMPLE
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If composite(k=5)=10=5*2 and 5-2=3(prime), then 5=a(1). If composite(k=7)=14=7*2 and 7-2=5(prime), then 7=a(2). If composite(k=8)=15=5*3 and 5-3=2(prime), then 8=a(3). If composite(k=11)=20=5*2*2 and 5-2=3(prime), then 11=a(4), etc.
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CROSSREFS
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Cf. A000040, A002808.
Sequence in context: A088299 A013635 A082728 this_sequence A045251 A099497 A061813
Adjacent sequences: A154367 A154368 A154369 this_sequence A154371 A154372 A154373
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KEYWORD
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nonn
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AUTHOR
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Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jan 08 2009
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