A083267 Product of related numbers (counted in A073757) belonging to n; related = {divisor-set, RRS}: a(n) = A007955(n)*A001783(n).

1, 2, 6, 24, 120, 180, 5040, 6720, 60480, 18900, 39916800, 665280, 6227020800, 3783780, 201801600, 2075673600, 355687428096000, 496215720, 121645100408832000, 69837768000, 20858213376000, 604969665300, 25852016738884976640000, 12336143339520, 5170403347776995328000

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..450

Example

For n = 10: related terms = {1,2,5,10,3,7,9}, product = 1*2*5*10*1*3*7*9 = 18900 = a(10).

Mathematica

a[n_] := n^(DivisorSigma[0, n]/2) * Times@@ Select[Range[n], CoprimeQ[n, #] &]; Array[a, 30] (* Amiram Eldar, Jun 20 2024 *)

Crossrefs

Cf. A073757 (count), A083266 (sum), A083268 (LCM), A083267 (product), A001783, A007955.

Sequence in context: A263709 A279435 A263699 * A130480 A000804 A048631

Adjacent sequences: A083264 A083265 A083266 * A083268 A083269 A083270

Keyword

nonn

Author

Labos Elemer, May 13 2003

Extensions

More terms from Amiram Eldar, Jun 20 2024

Status

approved