A288023 - cp's OEIS frontend

A288023 Number of steps to reach 1 in the Collatz 3x+1 problem starting with the n-th triangular number, or -1 if 1 is never reached.

n	a(n)
1	0
2	7
3	8
4	6
5	17
6	7
7	18
8	21
9	16
10	112
11	27
12	35
13	92
14	38
15	20
16	15
17	36
18	124
19	106
20	39
21	127
22	109
23	16
24	16
25	24
26	81
27	107
28	40
29	27
30	35
31	110
32	30
33	43
34	74
35	38
36	113
37	170
38	46
39	121
40	28
41	103
42	116
43	36
44	98
45	124
46	137
47	18
48	119
49	132
50	83
51	26
52	127
53	26
54	47
55	34
56	122
57	91
58	148
59	117
60	130
61	37
62	37
63	112
64	32
65	76
66	94
67	58
68	120
69	120
70	89
71	133
72	53
73	115
74	66

[0, 7, 8, 6, 17, 7, 18, 21, 16, 112, 27, 35, 92, 38, 20, 15, 36, 124, 106, 39, 127, 109, 16, 16, 24, 81, 107, 40, 27, 35, 110, 30, 43, 74, 38, 113, 170, 46, 121, 28, 103, 116, 36, 98, 124, 137, 18, 119, 132, 83, 26, 127, 26, 47, 34, 122, 91, 148, 117, 130, 37, 37, 112, 32, 76, 94, 58, 120, 120, 89, 133, 53, 115, 66]

cp's OEIS Frontend

A288023 Number of steps to reach 1 in the Collatz 3x+1 problem starting with the n-th triangular number, or -1 if 1 is never reached.

Table of values

List of values

n	a(n)
1	0
2	7
3	8
4	6
5	17
6	7
7	18
8	21
9	16
10	112
11	27
12	35
13	92
14	38
15	20
16	15
17	36
18	124
19	106
20	39
21	127
22	109
23	16
24	16
25	24
26	81
27	107
28	40
29	27
30	35
31	110
32	30
33	43
34	74
35	38
36	113
37	170
38	46
39	121
40	28
41	103
42	116
43	36
44	98
45	124
46	137
47	18
48	119
49	132
50	83
51	26
52	127
53	26
54	47
55	34
56	122
57	91
58	148
59	117
60	130
61	37
62	37
63	112
64	32
65	76
66	94
67	58
68	120
69	120
70	89
71	133
72	53
73	115
74	66

n	a(n)
1	0
2	7
3	8
4	6
5	17
6	7
7	18
8	21
9	16
10	112
11	27
12	35
13	92
14	38
15	20
16	15
17	36
18	124
19	106
20	39
21	127
22	109
23	16
24	16
25	24
26	81
27	107
28	40
29	27
30	35
31	110
32	30
33	43
34	74
35	38
36	113
37	170
38	46
39	121
40	28
41	103
42	116
43	36
44	98
45	124
46	137
47	18
48	119
49	132
50	83
51	26
52	127
53	26
54	47
55	34
56	122
57	91
58	148
59	117
60	130
61	37
62	37
63	112
64	32
65	76
66	94
67	58
68	120
69	120
70	89
71	133
72	53
73	115
74	66

n	a(n)
1	0
2	7
3	8
4	6
5	17
6	7
7	18
8	21
9	16
10	112
11	27
12	35
13	92
14	38
15	20
16	15
17	36
18	124
19	106
20	39
21	127
22	109
23	16
24	16
25	24
26	81
27	107
28	40
29	27
30	35
31	110
32	30
33	43
34	74
35	38
36	113
37	170
38	46
39	121
40	28
41	103
42	116
43	36
44	98
45	124
46	137
47	18
48	119
49	132
50	83
51	26
52	127
53	26
54	47
55	34
56	122
57	91
58	148
59	117
60	130
61	37
62	37
63	112
64	32
65	76
66	94
67	58
68	120
69	120
70	89
71	133
72	53
73	115
74	66