A206735 Triangle T(n,k), read by rows, given by (0, 2, -1/2, 1/2, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (1, 0, -1/2, 1/2, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938.
1, 0, 1, 0, 2, 1, 0, 3, 3, 1, 0, 4, 6, 4, 1, 0, 5, 10, 10, 5, 1, 0, 6, 15, 20, 15, 6, 1, 0, 7, 21, 35, 35, 21, 7, 1, 0, 8, 28, 56, 70, 56, 28, 8, 1, 0, 9, 36, 84, 126, 126, 84, 36, 9, 1, 0, 10, 45, 120, 210, 252, 210, 120, 45, 10, 1, 0, 11, 55, 165, 330, 462, 462, 330, 165, 55, 11, 1
Offset: 0
Examples
Triangle begins : 1 0, 1 0, 2, 1 0, 3, 3, 1 0, 4, 6, 4, 1 0, 5, 10, 10, 5, 1 0, 6, 15, 20, 15, 6, 1 0, 7, 21, 35, 35, 21, 7, 1 0, 8, 28, 56, 70, 56, 28, 8, 1 0, 9, 36, 84, 126, 126, 84, 36, 9, 1 0, 10, 45, 120, 210, 252, 210, 120, 45, 10, 1 0, 11, 55, 165, 330, 462, 462, 330, 165, 55, 11, 1
Formula
Sum_{k, 0<=k<=n} T(n,k)*x^k = (1+x)^n - 1 + 0^n.
T(n,0) = 0^n = A000007(n), T(n,k) = binomial(n,k) for k>0.
G.f.: (1-2*x+(1+y)*x^2)/(1-2x+(1+y)*x^2-y*x).
Comments