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A140386
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Primes of the form ((x+y)/3+2)/(x-y), where x=prime and y=composite.
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0
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5, 23, 29, 43, 107, 109, 137, 163, 197, 199, 227, 229, 317, 347, 359, 373, 389, 439, 449, 457, 463, 523, 569, 593, 599, 643, 709, 733, 743, 773, 787, 821, 823, 827, 835, 857, 883, 911, 919
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| x=p(i)=i-th prime and y=c(j)=j-th composite.
The current sequence is largely incorrect because many values are missing; for example x=17 with y=16 contributes 13, x=23 with y=22 contributes 17, x=53 with y=52 contributes 37 etc. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 25 2010]
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EXAMPLE
| If x=29 and y=25, then ((29+25)/3+2)/(29-25)=20/4=5=a(1).
If x=137 and y=133, then ((137+133)/3+2)/(137-133)=92/4=23=a(2).
If x=173 and y=169, then ((173+169)/3+2)/(173-169)=116/4=29=a(3).
If x=257 and y=253, then ((257+253)/3+2)/(257-253)=172/4=43=a(4).
If x=641 and y=637, then ((641+637)/3+2)/(641-637)=428/4=107=a(5).
If x=653 and y=649, then ((653+649)/3+2)/(653-649)=436/4=109=a(6),
etc.
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CROSSREFS
| Cf. A002808, A000040.
Sequence in context: A018527 A084411 A067367 * A105880 A163587 A038922
Adjacent sequences: A140383 A140384 A140385 * A140387 A140388 A140389
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KEYWORD
| nonn
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AUTHOR
| Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Aug 28 2008
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