A118381 Largest 3-smooth number dividing n!.

1, 2, 6, 24, 24, 144, 144, 1152, 10368, 20736, 20736, 248832, 248832, 497664, 1492992, 23887872, 23887872, 429981696, 429981696, 1719926784, 5159780352, 10319560704, 10319560704, 247669456896, 247669456896, 495338913792, 13374150672384, 53496602689536, 53496602689536

Offset: 1

Author

Reinhard Zumkeller, May 16 2006

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..1861 (terms below 10^1000)
• Index entries for sequences related to factorial numbers.

Crossrefs

Cf. A003586, A000142, A011371, A054861, A060818, A060828.

Programs

Mathematica

s[n_, b_] := Sum[IntegerExponent[k, b], {k, 1, n}]; a[n_] := 2^s[n, 2] * 3^s[n, 3]; Array[a, 30] (* Amiram Eldar, Jan 29 2020 *)

Formula

a(n) = A060818(n) * A060828(n).

Extensions

More terms from Amiram Eldar, Jan 29 2020