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A095134
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Sum of the product of the first floor(n/2) even-indexed primes and the product of the first floor(n/2) odd-indexed primes.
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3
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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
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OFFSET
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1,1
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LINKS
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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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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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