A167431 Riordan array (1-4x+4x^2, x(1-2x)).
1, -4, 1, 4, -6, 1, 0, 12, -8, 1, 0, -8, 24, -10, 1, 0, 0, -32, 40, -12, 1, 0, 0, 16, -80, 60, -14, 1, 0, 0, 0, 80, -160, 84, -16, 1, 0, 0, 0, -32, 240, -280, 112, -18, 1, 0, 0, 0, 0, -192, 560, -448, 144, -20, 1, 0, 0, 0, 0, 64, -672, 1120, -672, 180, -22, 1
Offset: 0
Examples
Triangle begins 1, -4, 1, 4, -6, 1, 0, 12, -8, 1, 0, -8, 24, -10, 1, 0, 0, -32, 40, -12, 1, 0, 0, 16, -80, 60, -14, 1, 0, 0, 0, 80, -160, 84, -16, 1, 0, 0, 0, -32, 240, -280, 112, -18, 1, 0, 0, 0, 0, -192, 560, -448, 144, -20, 1, 0, 0, 0, 0, 64, -672, 1120, -672, 180, -22, 1
Formula
T(n,k)=T(n-1,k-1)-2*T(n-2,k-1), T(0,0)=1, T(1,0)=-4, T(2,0)=4, T(n,k)=0 if k<0 or if k>n. - Philippe Deléham, Nov 13 2013
Comments