F(u,v)=∑i=0∞u⌊i/2⌋vii!F(u,v)=\sum_{i=0}^{\infty}\frac{u^{\lfloor i/2\rfloor}v^i}{i!}F(u,v)=∑i=0∞i!u⌊i/2⌋vi
求 [vn]F(u,v)D[v^n]F(u,v)^D[vn]F(u,v)D
