A(x;t)=t+(t+t^2)*x+(3*t+5*t^2+2*t^3)*x^2+(15*t+32*t^2+22*t^3+5*t^4)*x^3+。。。
三角形开始:
n\k[1][2][3][4][5][6][7][8]
[0] 1;
[1] 1, 1;
[2] 3, 5, 2;
[3] 15, 32, 22, 5;
[4] 105, 260, 234, 93, 14;
[5] 945, 2589, 2750, 1450, 386, 42;
[6] 10395, 30669, 36500, 22950, 8178, 1586, 132;
[7] 135135, 422232, 546476, 388136, 166110, 43400, 6476, 429;
[8] ...