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A089581
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Prime(2*n-1)*prime(2*n).
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2
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6, 35, 143, 323, 667, 1147, 1763, 2491, 3599, 4757, 5767, 7387, 9797, 11021, 12317, 16637, 19043, 22499, 25591, 28891, 32399, 36863, 39203, 47053, 51983, 55687, 60491, 67591, 72899, 77837, 82919, 95477, 99221, 111547, 121103, 126727, 136891
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| a(n+1) is the smallest squarefree composite number that is relatively prime to the first 2*n prime numbers.
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FORMULA
| prime(2*n-1)*prime(2*n), n=1, 2, 3 ...
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EXAMPLE
| a(13)=9797
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PROG
| (PARI) p=2; q=3; i=1; a=vector(100); for(i=1, 100, a[i]=p*q; p=nextprime(q+1); q=nextprime(p+1)); a
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CROSSREFS
| Sequence in context: A101077 A094952 A024526 * A132657 A161784 A027985
Adjacent sequences: A089578 A089579 A089580 * A089582 A089583 A089584
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KEYWORD
| easy,nonn
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AUTHOR
| Norbert A'Campo (nac(AT)member.ams.org), Dec 29 2003
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EXTENSIONS
| Edited by Zak Seidov, Jun 13 2006
Typo in PARI program fixed by Zak Seidov (zakseidov(AT)yahoo.com), May 19 2010
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