A076891 a(n) = [n/1][n/2][n/3] ...[n/n] / n^(tau(n)/2).

1, 1, 1, 1, 2, 1, 6, 2, 8, 6, 60, 2, 288, 48, 84, 60, 3840, 48, 15552, 144, 4800, 10080, 221760, 96, 331776, 138240, 224640, 25920, 20321280, 4032, 108864000, 345600, 17694720, 36495360, 51701760, 40320, 11287019520, 627056640, 992839680

Offset: 1

Author

Benoit Cloitre, Nov 26 2002

Keywords

• nonn

Crossrefs

Cf. A000005 (tau), A007955, A010786.

Programs

Mathematica

a[n_] := Product[Floor[n/k], {k, 1, n}] / n^(DivisorSigma[0, n]/2); Array[a, 40] (* Amiram Eldar, Apr 08 2024 *)

PARI

a(n) = prod(k = 1, n, n\k) / n^(numdiv(n)/2); \\ Amiram Eldar, Apr 08 2024

Formula

a(n) = A010786(n)/n^(A000005(n)/2) = A010786(n)/A007955(n).