A098446 Triangle, read by rows, such that T(n,k) equals the k-th term of the convolution of the (n-1)-th diagonal with the k-th row of this triangle.
1, 1, 1, 1, 2, 1, 1, 3, 4, 1, 1, 4, 9, 9, 1, 1, 5, 16, 30, 24, 1, 1, 6, 25, 70, 115, 77, 1, 1, 7, 36, 135, 344, 510, 295, 1, 1, 8, 49, 231, 805, 1908, 2602, 1329, 1, 1, 9, 64, 364, 1616, 5325, 11904, 15133, 6934, 1, 1, 10, 81, 540, 2919, 12381, 39001, 83028, 99367, 41351, 1
Offset: 0
Examples
T(7,3) = T(3,0)*T(6,3) + T(3,1)*T(5,2) + T(3,2)*T(4,1) + T(3,3)*T(3,0) = 1*70 + 3*16 + 4*4 + 1*1 = 135. Rows begin: [1], [1,1], [1,2,1], [1,3,4,1], [1,4,9,9,1], [1,5,16,30,24,1], [1,6,25,70,115,77,1], [1,7,36,135,344,510,295,1], [1,8,49,231,805,1908,2602,1329,1], [1,9,64,364,1616,5325,11904,15133,6934,1],...
Programs
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PARI
T(n,k)=if(n
Formula
T(n, k) = Sum_{i=0..k} T(k, i)*T(n-i-1, k-i) for 0
Comments