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Search: id:A125903
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| A125903 |
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a(n) = product of the first n primes which are coprime to n. |
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+0
2
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| 2, 15, 70, 1155, 6006, 1616615, 1385670, 111546435, 2156564410, 742073813481, 674612557710, 2180460221945005, 1006366256282310, 2327797034085003195, 128184023343614175938, 961380175077106319535, 6899316550553351234310
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OFFSET
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1,1
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EXAMPLE
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The first 6 primes which are coprime to 6 are 5,7,11,13,17,19. So a(6)=5*7*11*13*17*19 = 1616615.
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MATHEMATICA
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f[n_] := Block[{c = n, k = 0, p, t = 1}, While[c > 0, k++; While[p = Prime[k]; GCD[p, n] > 1, k++ ]; c--; t *= p; ]; t]; Table[f[n], {n, 17}] (*Chandler*)
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CROSSREFS
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Cf. A119993, A125902.
Sequence in context: A055206 A091135 A056037 this_sequence A007232 A099743 A102289
Adjacent sequences: A125900 A125901 A125902 this_sequence A125904 A125905 A125906
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), Dec 13 2006
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EXTENSIONS
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Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Dec 14 2006
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