A(x;t)=x+(2*t+2)*x^2/2!+(9*t^2+15*t+8)*x^3/3!+(64*t^3+156*t^2+144*t+52)*x^4/4!+。。。
三角形开始:
n\k[1][2][3][4][5][6][7]
[1] 1;
[2] 2, 2;
[3] 9, 15, 8;
[4] 64, 156, 144, 52;
[5] 625, 2050, 2675, 1730, 472;
[6] 7776, 32430, 55000, 50310, 25108, 5504;
[7] 117649, 599319, 1258775, 1484245, 1052184, 428036, 78416;
[8] ...