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A154297
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Primes of the form : 1/x+2/x+3/x+4/x+5/x+6/x+7/x+..., x=21.
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2
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OFFSET
| 1,1
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COMMENTS
| This asks for primes p which are a triangular number divided by 21, or, 2*3*7*p=k*(k+1) for some k. Matching factors shows that the sequence is complete [R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 15 2010]
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MATHEMATICA
| lst={}; s=0; Do[s+=n/21; If[Floor[s]==s, If[PrimeQ[s], AppendTo[lst, s]]], {n, 0, 9!}]; lst
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CROSSREFS
| Cf. A057570, A154293, A154296
Sequence in context: A197337 A187984 A063626 * A089441 A046121 A023271
Adjacent sequences: A154294 A154295 A154296 * A154298 A154299 A154300
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KEYWORD
| nonn,fini,full
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AUTHOR
| Vladimir Orlovsky (4vladimir(AT)gmail.com), Jan 06 2009
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EXTENSIONS
| Added keyword:fini,full - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 15 2010
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