A245334 A factorial-like triangle read by rows: T(0,0) = 1; T(n+1,0) = T(n,0)+1; T(n+1,k+1) = T(n,0)*T(n,k), k=0..n.
1, 2, 1, 3, 4, 2, 4, 9, 12, 6, 5, 16, 36, 48, 24, 6, 25, 80, 180, 240, 120, 7, 36, 150, 480, 1080, 1440, 720, 8, 49, 252, 1050, 3360, 7560, 10080, 5040, 9, 64, 392, 2016, 8400, 26880, 60480, 80640, 40320, 10, 81, 576, 3528, 18144, 75600, 241920, 544320
Offset: 0
Examples
. 0: 1; . 1: 2, 1; . 2: 3, 4, 2; . 3: 4, 9, 12, 6; . 4: 5, 16, 36, 48, 24; . 5: 6, 25, 80, 180, 240, 120; . 6: 7, 36, 150, 480, 1080, 1440, 720; . 7: 8, 49, 252, 1050, 3360, 7560, 10080, 5040; . 8: 9, 64, 392, 2016, 8400, 26880, 60480, 80640, 40320; . 9: 10, 81, 576, 3528, 18144, 75600, 241920, 544320, 725760, 362880.
Links
- Reinhard Zumkeller, Rows n = 0..125 of triangle, flattened
Crossrefs
Programs
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Haskell
a245334 n k = a245334_tabl !! n !! k a245334_row n = a245334_tabl !! n a245334_tabl = iterate (\row@(h:_) -> (h + 1) : map (* h) row) [1]
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Mathematica
Table[(n!)/((n - k)!)*(n + 1 - k), {n, 0, 9}, {k, 0, n}] // Flatten (* Michael De Vlieger, Sep 10 2017 *)
Formula
T(n,k) = n!*(n+1-k)/(n-k)!. - Werner Schulte, Sep 09 2017
Comments