def u(n , U = None):
    if not U:
        U = [(1,0)] + [(None,None)] * n
    if U[n][0] == None:
        val = u(n-1 , U)[1] + n * u(n-1 , U)[0]
        U[n] = (val / n , val)
    return U[n]

for n in range(20):
    print( u(n)[0] )