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A182370
a(n) = (n!)!/(n!^(n-1)!).
0
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.
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
KEYWORD
nonn
AUTHOR
Michel Lagneau, Apr 26 2012
STATUS
approved