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Search: id:A095137
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| A095137 |
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Absolute difference between 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, 1, 7, 11, 89, 163, 1597, 3317, 37823, 107413, 1182887, 4232341, 49100059, 184657283, 2329965377, 10114830259, 138903895201, 622143222539, 9382665690241, 44778520855589, 686482057860331, 3598441529151191
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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the absolute difference 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 = 89, a(6) = 3*7*13 - 2*5*11 = 163, a(7) =
2*5*11*17 - 3*7*13 = 1597, a(8) = 3*7*13*19 - 2*5*11*17 = 3317.
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MATHEMATICA
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PrimeFactors[n_] := Flatten[ Table[ #[[1]], {1} ] & /@ FactorInteger[n]]; f[n_] := Abs[ Product[ Prime[i], {i, 2, n, 2}] + Product[ Prime[i], {i, 1, n, 2}]]; f[1] = 2; Table[ f[n], {n, 24}]
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CROSSREFS
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Cf. A095134, A000040, A066206, A066205.
Sequence in context: A032039 A075118 A100245 this_sequence A141488 A113042 A013070
Adjacent sequences: A095134 A095135 A095136 this_sequence A095138 A095139 A095140
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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 28 2004
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