def densenet_params(model_name):
    """ Map densenet_pytorch model name to parameter coefficients. """
    params_dict = {'densenet121': (32, 64, 224), 'densenet161': (48, 96, 
        224), 'densenet169': (32, 64, 224), 'densenet201': (32, 64, 224)}
    return params_dict[model_name]
