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A277174
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a(n) = Product_{i=1..n} i*rad(i) where rad(n) = A007947(n).
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2
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1, 1, 4, 36, 288, 7200, 259200, 12700800, 203212800, 5486745600, 548674560000, 66389621760000, 4780052766720000, 807828917575680000, 158334467844833280000, 35625255265087488000000, 1140008168482799616000000, 329462360691529089024000000
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OFFSET
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0,3
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LINKS
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FORMULA
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MAPLE
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rad := n -> mul(k, k in numtheory:-factorset(n));
mul(i * rad(i), i=1..n) end:
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MATHEMATICA
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Table[Product[i Last@ Select[Divisors@ i, SquareFreeQ], {i, n}], {n, 0, 17}] (* Michael De Vlieger, Oct 02 2016 *)
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PROG
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(PARI) a(n) = prod(i=1, n, i*factorback(factorint(i)[, 1])); \\ Michel Marcus, Oct 03 2016
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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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