def triangles(number_max):    list_num = [1]    list_mid = []    for n in range(1, number_max+1):        yield list_num        list_num.insert(0, 0)        [list_mid.append(list_num[m] + list_num[n - m]) for m in range(n + 1)]        list_num = list_mid.copy()        list_mid.clear()