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Search: id:A095134
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| A095134 |
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Sum of the product of the first [n/2] even indexed primes and the product of the first [n/2] odd indexed primes. |
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+0
4
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| 2, 5, 13, 31, 131, 383, 2143, 7057, 48197, 193433, 1483733, 6898961, 60231361, 293988703, 2808611363, 15253406999, 164272132459, 925319250199, 10930128162979, 65091314708809, 796351893424729, 5081275480436251
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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sum_{i=1..n} of the product_{j=2..n, 2} p_j (A066206) and the product_{k=1..n, 2} p_j (A066205).
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EXAMPLE
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a(5) = 2*5*11 + 3*7 = 131, a(6) = 2*5*11 + 3*7*13 = 383, a(7) =
2*5*11*17 + 3*7*13 = 2143, a(8) = 2*5*11*17 + 3*7*13*19 = 7057.
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MATHEMATICA
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f[n_] := Product[Prime[i], {i, 2, n, 2}] + Product[Prime[i], {i, 1, n, 2}]; f[1] = 2; Table[ f[n], {n, 22}]
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CROSSREFS
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Cf. A095137, A000040, A066206, A066205.
Sequence in context: A099515 A056367 A082733 this_sequence A086758 A116702 A098156
Adjacent sequences: A095131 A095132 A095133 this_sequence A095135 A095136 A095137
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), May 27 2004
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