A220271 Product of the radicals of the integers less than n and relatively prime to n.

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

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 A361323 A292265

Adjacent sequences: A220268 A220269 A220270 * A220272 A220273 A220274

Keyword

nonn

Author

Michel Marcus, Dec 09 2012

Status

approved