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A262032
a(n) = (2^n)! / n!.
0
1, 2, 12, 6720, 871782912000, 2192756974447446084726816768000000, 176231850258172450143657485187724278892868772464646100276113742187798200320000000000000
OFFSET
0,2
FORMULA
a(n) = A000722(n) / A000142(n).
EXAMPLE
For n = 2, a(n) = (2^n)! / n! = (2^2)! / 2! = 12.
MATHEMATICA
Table[(2^n)!/n!, {n, 0, 6}] (* Michael De Vlieger, Sep 09 2015 *)
PROG
(PARI) a(n) = (2^n)! / n!;
vector(10, n, a(n-1))
(Magma) [Factorial(2^n) / Factorial(n): n in [0..7]]; // Vincenzo Librandi, Sep 10 2015
CROSSREFS
Sequence in context: A118542 A007155 A265092 * A074200 A342104 A274223
KEYWORD
nonn,easy
AUTHOR
Altug Alkan, Sep 08 2015
STATUS
approved