A177517 Triangle T(n,k) read by rows defined by recurrence T(n,1)=A000007(n-1) and T(n,k) = sum_{i=1..k-1} T(n-i,k-1) if k>1.
1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 2, 1, 0, 0, 0, 2, 3, 1, 0, 0, 0, 1, 5, 4, 1, 0, 0, 0, 0, 6, 9, 5, 1, 0, 0, 0, 0, 5, 15, 14, 6, 1, 0, 0, 0, 0, 3, 20, 29, 20, 7, 1, 0, 0, 0, 0, 1, 22, 49, 49, 27, 8, 1, 0, 0, 0, 0, 0, 20, 71, 98, 76, 35, 9, 1, 0, 0, 0, 0, 0, 15, 90, 169, 174, 111, 44, 10, 1, 0, 0, 0, 0, 0, 9, 101, 259, 343, 285, 155, 54, 11, 1, 0, 0, 0, 0, 0, 4, 101, 359, 602, 628, 440, 209, 65, 12, 1, 0, 0, 0, 0, 0, 1, 90, 455, 961, 1230, 1068, 649, 274, 77, 13, 1
Offset: 1
Examples
1, 0,1, 0,0,1, 0,0,1,1, 0,0,0,2,1, 0,0,0,2,3,1, 0,0,0,1,5,4,1, 0,0,0,0,6,9,5,1, 0,0,0,0,5,15,14,6,1, 0,0,0,0,3,20,29,20,7,1, 0,0,0,0,1,22,49,49,27,8,1
Links
- Alois P. Heinz, Table of n, a(n) for n = 1..20301
Programs
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Mathematica
t[1, 1] = 1; t[n_, 1] = 0; t[n_, k_] := t[n, k] = If[n >= k, Sum[t[n - i, k - 1], {i, 1, k - 1}], 0]; Flatten[Table[t[n, k], {n, 12}, {k, n}]] (* Robert G. Wilson v, Jun 24 2011 *) (* corrected by Mats Granvik, Jan 23 2012 *)
Formula
T(n,k) = A008302(k-2,n-k), n>=k>1. - R. J. Mathar, Dec 15 2010
Comments