A304030 - cp's OEIS frontend

A304030 a(n) is the number of steps at which the Collatz ('3x+1') trajectory of n crosses its initial value, or -1 if the number of crossings is infinite.

n	a(n)
1	0
2	0
3	1
4	0
5	1
6	4
7	3
8	0
9	5
10	2
11	3
12	2
13	3
14	8
15	3
16	0
17	3
18	10
19	7
20	0
21	1
22	6
23	1
24	0
25	9
26	2
27	3
28	6
29	7
30	4
31	3
32	0
33	13
34	4
35	1
36	4
37	5
38	8
39	9
40	0
41	7
42	2
43	5
44	2
45	3
46	4
47	5
48	0
49	5
50	8
51	5
52	0
53	1
54	14
55	9
56	0
57	7
58	2
59	3
60	6
61	7
62	12
63	9
64	0
65	5
66	6
67	3
68	0
69	1
70	4
71	7
72	0
73	13
74	2
75	1
76	2
77	3
78	8
79	3
80	0
81	7
82	14
83	11
84	0
85	1
86	8
87	3
88	0
89	3
90	2
91	7
92	4
93	5
94	12
95	9
96	0
97	19
98	4
99	1
100	0

[0, 0, 1, 0, 1, 4, 3, 0, 5, 2, 3, 2, 3, 8, 3, 0, 3, 10, 7, 0, 1, 6, 1, 0, 9, 2, 3, 6, 7, 4, 3, 0, 13, 4, 1, 4, 5, 8, 9, 0, 7, 2, 5, 2, 3, 4, 5, 0, 5, 8, 5, 0, 1, 14, 9, 0, 7, 2, 3, 6, 7, 12, 9, 0, 5, 6, 3, 0, 1, 4, 7, 0, 13, 2, 1, 2, 3, 8, 3, 0, 7, 14, 11, 0, 1, 8, 3, 0, 3, 2, 7, 4, 5, 12, 9, 0, 19, 4, 1, 0]

cp's OEIS Frontend

A304030 a(n) is the number of steps at which the Collatz ('3x+1') trajectory of n crosses its initial value, or -1 if the number of crossings is infinite.

Table of values

List of values

n	a(n)
1	0
2	0
3	1
4	0
5	1
6	4
7	3
8	0
9	5
10	2
11	3
12	2
13	3
14	8
15	3
16	0
17	3
18	10
19	7
20	0
21	1
22	6
23	1
24	0
25	9
26	2
27	3
28	6
29	7
30	4
31	3
32	0
33	13
34	4
35	1
36	4
37	5
38	8
39	9
40	0
41	7
42	2
43	5
44	2
45	3
46	4
47	5
48	0
49	5
50	8
51	5
52	0
53	1
54	14
55	9
56	0
57	7
58	2
59	3
60	6
61	7
62	12
63	9
64	0
65	5
66	6
67	3
68	0
69	1
70	4
71	7
72	0
73	13
74	2
75	1
76	2
77	3
78	8
79	3
80	0
81	7
82	14
83	11
84	0
85	1
86	8
87	3
88	0
89	3
90	2
91	7
92	4
93	5
94	12
95	9
96	0
97	19
98	4
99	1
100	0

n	a(n)
1	0
2	0
3	1
4	0
5	1
6	4
7	3
8	0
9	5
10	2
11	3
12	2
13	3
14	8
15	3
16	0
17	3
18	10
19	7
20	0
21	1
22	6
23	1
24	0
25	9
26	2
27	3
28	6
29	7
30	4
31	3
32	0
33	13
34	4
35	1
36	4
37	5
38	8
39	9
40	0
41	7
42	2
43	5
44	2
45	3
46	4
47	5
48	0
49	5
50	8
51	5
52	0
53	1
54	14
55	9
56	0
57	7
58	2
59	3
60	6
61	7
62	12
63	9
64	0
65	5
66	6
67	3
68	0
69	1
70	4
71	7
72	0
73	13
74	2
75	1
76	2
77	3
78	8
79	3
80	0
81	7
82	14
83	11
84	0
85	1
86	8
87	3
88	0
89	3
90	2
91	7
92	4
93	5
94	12
95	9
96	0
97	19
98	4
99	1
100	0

n	a(n)
1	0
2	0
3	1
4	0
5	1
6	4
7	3
8	0
9	5
10	2
11	3
12	2
13	3
14	8
15	3
16	0
17	3
18	10
19	7
20	0
21	1
22	6
23	1
24	0
25	9
26	2
27	3
28	6
29	7
30	4
31	3
32	0
33	13
34	4
35	1
36	4
37	5
38	8
39	9
40	0
41	7
42	2
43	5
44	2
45	3
46	4
47	5
48	0
49	5
50	8
51	5
52	0
53	1
54	14
55	9
56	0
57	7
58	2
59	3
60	6
61	7
62	12
63	9
64	0
65	5
66	6
67	3
68	0
69	1
70	4
71	7
72	0
73	13
74	2
75	1
76	2
77	3
78	8
79	3
80	0
81	7
82	14
83	11
84	0
85	1
86	8
87	3
88	0
89	3
90	2
91	7
92	4
93	5
94	12
95	9
96	0
97	19
98	4
99	1
100	0