A107842 A number triangle of lattice walks.

1, 2, 1, 5, 5, 1, 14, 20, 8, 1, 42, 75, 44, 11, 1, 132, 275, 208, 77, 14, 1, 429, 1001, 910, 440, 119, 17, 1, 1430, 3640, 3808, 2244, 798, 170, 20, 1, 4862, 13260, 15504, 10659, 4655, 1309, 230, 23, 1, 16796, 48450, 62016, 48279, 24794, 8602, 2000, 299, 26, 1

Offset: 0

Author

Paul Barry, May 24 2005

Keywords

• easy
• nonn
• tabl

Comments

First column is A000108(n+1). Columns include A000344, A003518 and A000589. Row sums are A026671. Compare [1,1,1,...] DELTA [0,1,0,0,...] where DELTA is the operator defined in A084938.

Transposed version in A109450. - Philippe Deléham, Jun 05 2007

Examples

			Triangle begins
   1;
   2,  1;
   5,  5,  1;
  14, 20,  8,  1;
  42, 75, 44, 11,  1;
Triangle [1,1,1,1,1,...] DELTA [0,1,0,0,0,0,...] begins:
    1;
    1,   0;
    2,   1,   0;
    5,   5,   1,   0;
   14,  20,   8,   1,   0;
   42,  75,  44,  11,   1,   0;
  132, 275, 208,  77,  14,   1,   0; ...
		

Links

• Paul Barry, Chebyshev moments and Riordan involutions, arXiv:1912.11845 [math.CO], 2019.

Formula

Number triangle T(n, k) = (3k+2)*C(2n+k+1, n-k)/(n+2k+2).

Column k has g.f.: x^k*C(x)^(3k+2) where C(x) is the g.f. of A000108.