def iteration_speed_lower_bound(l, k, time_arr):
    """
    Compute almost-lower bound.

    Parameters
    ----------
    l : float
        Lambda (exponential rate).
    k : int
        Graph's degree.
    time_arr : list of float
        #iter -> completion time fo such iteration.

    Returns
    -------
    list of float
    """

    lb = []
    for t in time_arr:
        lb.append(t * l / (1 + sum(1 / i for i in range(1, k + 1))))
    return lb