def collatz(u):
    r,p=1,2
    while 1:
        r=(-r)%6
        a=(p*r-1)//3
        p*=2  
        if (u-a)%p==0:
            return 6*((u-a)//p)+r
 
def f(u):
    c=str(u)
    while u>1:
        u=collatz(u)
        c+=', '+str(u)
    print(c)
    with open('collatz_{}.txt'.format(u), 'w') as fp:
        fp.write(c)
 
#collatz(155)
f(155)

U = 155  # Den Algorithmus durchlaufende Zahl
def collatz(u):
    r,p=1,2
    while 1:
        r=(-r)%6
        a=(p*r-1)//3
        p*=2  
        if (u-a)%p==0:
            return 6*((u-a)//p)+r
def f(u):
    c=str(u)
    while u>1:
        u=collatz(u)
        c+='\n'+str(u)
#    print(c)                       # alt
    print(c.replace("\n",", "))     # neu
    with open('collatz_{}.txt'.format(U), 'w') as fp:
        fp.write(c)
#collatz(U)
f(U)

155, 233, 175, 263, 395, 593, 445, 167, 251, 
377, 283, 425, 319, 479, 719, 1079, 1619, 
2429, 911, 1367, 2051, 3077, 577, 433, 
325, 61, 23, 35, 53, 5, 1

155
233
175
263
395
593
...