A119828 Number triangle T(n,k)=(2n)!/(2k)!.
1, 2, 1, 24, 12, 1, 720, 360, 30, 1, 40320, 20160, 1680, 56, 1, 3628800, 1814400, 151200, 5040, 90, 1, 479001600, 239500800, 19958400, 665280, 11880, 132, 1, 87178291200, 43589145600, 3632428800, 121080960, 2162160, 24024, 182, 1
Offset: 0
Examples
Triangle begins as: 1, 2, 1, 24, 12, 1, 720, 360, 30, 1, 40320, 20160, 1680, 56, 1, 3628800, 1814400, 151200, 5040, 90, 1
Programs
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Mathematica
Flatten[Table[(2n)!/(2k)!, {n, 0, 7}, {k, 0, n}]] (* James C. McMahon, Sep 23 2024 *)
Formula
Number triangle T(n,k)=[k<=n](2n)!/(2k)!
Comments