def compute_min_value(ad_bits):
    """Compute the min value for the codebook with codewords of length ad_bits

    :param ad_bits: codeword length
    :type ad_bits: int
    :return: min value
    :rtype: int
    """
    tab = [0, None, 1, 6, 18, 83, 376, 1264, 5263, 17580, 72910]
    return tab[ad_bits]