A182370 a(n) = (n!)!/(n!^(n-1)!).

1, 1, 20, 3246670537110000

Offset

1,3

Comments

n^(n-1)! divides (n!)! because the product (n!)! = 1*2*3*...*n*(n+1)*...*n! contains (n-1)! divisors such that n, 2n, 3n,...,(n-1)!*n = n!

a(5) contains 149 digits; a(6) contains 1404 decimal digits; a(7) contains 13808 decimal digits; a(8) contains 144975 decimal digits.

Links

Table of n, a(n) for n=1..4.

Maple

for n from 1 to 5 do: x:= (n!)!/(n!^(n-1)!): printf(`%d, `, k):od:

Crossrefs

Cf. A000142.

Sequence in context: A048948 A172834 A271976 * A259331 A364863 A209614

Adjacent sequences: A182367 A182368 A182369 * A182371 A182372 A182373

Keyword

nonn

Author

Michel Lagneau, Apr 26 2012

Status

approved