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A141284
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Nonprimes of the form ((p(max)-1)*..*p*(p(min)+2)), where (p(max))*..*p*(p(min) = k(n) =n-th composite.
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3
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4, 8, 8, 10, 16, 16, 24, 20, 16, 24, 32, 30, 40, 32, 28, 48, 30, 48, 48, 32, 50, 64, 42, 48, 72, 60, 64, 72, 80, 60, 88, 64, 54, 80, 80, 96, 72, 70, 96, 90, 112, 96, 120, 90, 64, 84, 120, 128, 110, 120, 96, 144, 100, 144, 90, 144, 128, 90, 160, 144, 112, 168, 140, 160
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Replace one instance of the largest prime factor A052369(n) in the n-th composite by A052369(n)-1,
one instance of the smallest prime factor A056608(n) in the n-th composite by A056608(n)+2,
and if the result is composite, add it to the sequence. In summary, the sequence
contains composites of the form A002808(n)*(A052369(n)-1)*(A056608(n)+2)/(A052369(n)*A056608(n)).
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EXAMPLE
| If k(1)=4=(p(max)=2)*(p(min)=2), then (2-1)*(2+2)=1*4=4 .
If k(2)=8=(p(max)=3)*(p(min)=2), then
(3-1)*(2+2)=2*4=8 .
If k(3)=8=(p(max)=2)*(p=2)*(p(min)=2), then
(2-1)*2*(2+2)=1*2*4=8, etc.
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CROSSREFS
| Sequence in context: A040012 A054006 A029679 * A145154 A072541 A141719
Adjacent sequences: A141281 A141282 A141283 * A141285 A141286 A141287
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KEYWORD
| nonn
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AUTHOR
| Juri-Stepan Gerasimov (2stepan(AT)rambler.ru) Aug 08 2008
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EXTENSIONS
| Definition and examples corrected and entries checked by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 29 2010
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