polinomis de sumes de factorial

P[n](-1) = (-1)·( 0!+1!+...+n! )

(-1)·P[n](-1) = ( 0!+1!+...+n! )

P[n+1](x) = d_{x}[ P[n](x) ]+(1/x)

P[0](x) = (1/x)

P[1](x) = (-1)·(1/x^{2})+(1/x)

P[2](x) = 2·(1/x^{3})+(-1)·(1/x^{2})+(1/x)

P[3](x) = (-6)·(1/x^{4})+2·(1/x^{3})+(-1)·(1/x^{2})+(1/x)