A143983 Triangle T(n,k), n>=1, 1<=k<=n, read by rows, where sequence a_k of column k has a_k(0)=1, followed by (k-1)-fold 0 and a_k(n) shifts k places down under binomial transform.
1, 2, 1, 5, 1, 1, 15, 2, 1, 1, 52, 5, 1, 1, 1, 203, 13, 2, 1, 1, 1, 877, 36, 6, 1, 1, 1, 1, 4140, 109, 17, 2, 1, 1, 1, 1, 21147, 359, 44, 7, 1, 1, 1, 1, 1, 115975, 1266, 112, 23, 2, 1, 1, 1, 1, 1, 678570, 4731, 304, 65, 8, 1, 1, 1, 1, 1, 1, 4213597, 18657, 918, 165, 30, 2, 1, 1, 1, 1, 1, 1
Offset: 1
Examples
T(5,2) = 5, because [1,3,3,1] * [1,0,1,1] = 5. Triangle begins: : 1; : 2, 1; : 5, 1, 1; : 15, 2, 1, 1; : 52, 5, 1, 1, 1; : 203, 13, 2, 1, 1, 1; : 877, 36, 6, 1, 1, 1, 1; : 4140, 109, 17, 2, 1, 1, 1, 1; : 21147, 359, 44, 7, 1, 1, 1, 1, 1; : 115975, 1266, 112, 23, 2, 1, 1, 1, 1, 1;
Links
- Alois P. Heinz, Rows n = 1..141, flattened
- N. J. A. Sloane, Transforms
Programs
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Maple
T:= proc(n, k) option remember; `if`(n
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Mathematica
t[n_, k_] := t[n, k] = If[n < k, If[n == 0, 1, 0], Sum[Binomial[n-k, j]*t[j, k], {j, 0, n-k}]]; Table[Table[t[n, k], {k, 1, n}], {n, 1, 13}] // Flatten (* Jean-François Alcover, Dec 18 2013, translated from Maple *)
Formula
T(n,k) = Sum_{j=0..n-k} C(n-k,j)*T(j,k) if n>=k, else T(n,k) = 1 if n=1, else T(n,k) = 0.
Comments