def get_mixture_weights_index_tuples(n_mixtures):
    """Index tuples for mixture_weight.

    Args:
        n_mixtures (int): Number of elements in the mixture distribution of the factors.

    Returns:
        ind_tups (list)

    """
    ind_tups = []
    for emf in range(n_mixtures):
        ind_tups.append(("mixture_weights", 0, f"mixture_{emf}", "-"))
    return ind_tups