def hello_world():
  return 'hello_world'

def create_num_list(length):
  return [x for x in range(length)]

def custom_func_x(x, const, power):
  return const * (x) ** power

def custom_non_lin_num_list(length, const, power):
  return [custom_func_x(x, const, power) for x in range(length)]