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A220271 Product of the radicals of the integers less than n and relatively prime to n. 0
1, 1, 2, 3, 12, 5, 360, 105, 280, 63, 151200, 385, 9979200, 6435, 112112, 675675, 54486432000, 85085, 5557616064000, 2909907, 369512000, 416645775, 487847538097920000, 37182145, 8976394701001728, 40542838875, 2382036937280000, 10756263375 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..28.

C. M. Petridi, Note on the radicals of numbers, arXiv:math/0608014.

MATHEMATICA

Table[prod = 1; Do[If[GCD[n, i] == 1, prod = prod*Times @@ Transpose[FactorInteger[i]][[1]]], {i, n - 1}]; prod, {n, 30}] (* T. D. Noe, Dec 10 2012 *)

PROG

(PARI) a(n) = {local(p); p = 1; for (i=1, n, if (gcd(i, n) == 1, p *= A007947(i)); ); return (p); }

CROSSREFS

Cf. A007947.

Sequence in context: A325760 A056819 A124442 * A088611 A292265 A259416

Adjacent sequences:  A220268 A220269 A220270 * A220272 A220273 A220274

KEYWORD

nonn

AUTHOR

Michel Marcus, Dec 09 2012

STATUS

approved

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Last modified May 28 04:02 EDT 2022. Contains 354112 sequences. (Running on oeis4.)