Terse Schroeder & Abel function code

[Daniel]

The Pari/GP code for Bell polynomials is

Code:

  Bell(k,n=-1)=
  { my(x, v, dv, var = i->eval(Str("X",i)));
 
    v = vector(k, i, if (i==1, 'E, var(i-1)));
    dv = vector(k, i, if (i==1, 'X*var(1)*'E, var(i)));
    x = diffop('E,v,dv,k) / 'E;
    if (n < 0, subst(x,'X,1), polcoef(x,n,'X));
  }

So to Mathematica code at the beginning of this thread can be migrated to Pari/GP.