def get_exp_decay_layer_list(start_width, final_output_layer=15, decay_rate=2, max_layers=None):
    """
    Get a list of layers that decay over two until we reach the final output layer.
    Layers list used to control width and depth in modules.
    """
    layers = []
    v = start_width
    while v > final_output_layer*decay_rate:
        if max_layers and len(layers) == max_layers:
            print(layers)
            return layers
        v = v//decay_rate
        layers.append(v)

    print(layers)
    return layers