OFFSET
0,2
COMMENTS
FORMULA
Number triangle T(n,k) = Sum_{j=0..n} C(n, j)*C(j+k, 2k);
T(n,k) = Sum_{j=0..n} C(n, k+j)*C(k, k-j)*2^(n-k-j);
T(n,k) = Sum_{j=0..n-k} C(n+k-j, n-k-j)*C(k, j)*(-1)^j*2^(n-k-j).
T(n,k) = 4*T(n-1,k) + T(n-1,k-1) - 4*T(n-2,k) - T(n-2,k-1), T(0,0) = T(1,1) = 1, T(1,0) = 2, T(n,k) = 0 if k < 0 or if k > n. - Philippe Deléham, Jan 17 2014
EXAMPLE
Triangle begins:
1;
2, 1;
4, 5, 1;
8, 18, 8, 1;
16, 56, 41, 11, 1;
32, 160, 170, 73, 14, 1;
...
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, Nov 15 2005
EXTENSIONS
More terms from Michel Marcus, Sep 09 2024
STATUS
approved