A(x;t)=x+(1+2*t)*x^2+(7+6*t)*x^3+(63+74*t+10*t^2)*x*4+。..
三角形开始:
n\k[0][1][2][3][4][5]
[1] 1;
[2] 1, 2;
[3] 7, 6;
[4] 63, 74, 10;
[5] 729, 974, 254, 8;
[6] 10113, 15084, 5376, 406;
[7] 161935, 264724, 117424, 14954, 320;
[8] 2923135, 5163276, 2697804, 481222, 23670, 112;
[9] 58547761, 110483028, 65662932, 14892090, 1186362, 21936;
[10] ...