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A281019
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Partial products of A051953; a(1) = 1.
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1
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1, 1, 1, 2, 2, 8, 8, 32, 96, 576, 576, 4608, 4608, 36864, 258048, 2064384, 2064384, 24772608, 24772608, 297271296, 2675441664, 32105299968, 32105299968, 513684799488, 2568423997440, 35957935964160, 323621423677440, 5177942778839040, 5177942778839040
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OFFSET
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1,4
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LINKS
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FORMULA
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a(1) = 1; for n>1, a(n) = Product_{i=2..n} A051953(i).
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MATHEMATICA
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Table[If[n==1, 1, Product[i - EulerPhi[i], {i, 2, n}]], {n, 1, 29}] (* Indranil Ghosh, Mar 09 2017 *)
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PROG
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(Magma) [1] cat [&*[#[h: h in [2..k] | GCD(h, k) ne 1]: k in [2..n]]: n in [2..100]]
(PARI) for (n=1, 29, print1(if(n==1, 1, prod(i=2, n, i - eulerphi(i))), ", ")); \\ Indranil Ghosh, Mar 09 2017
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CROSSREFS
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Cf. A051953(n) = number of cototatives of n.
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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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