A087263 - cp's OEIS frontend

A087263 a(n) is the least initial value of a 3x+1 trajectory in which n is the largest (peak) term or a(n) = 0 if n cannot be a peak value (i.e., when n = 2k+1, n = 4k+2, n = 16k+12, etc.).

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

[1, 2, 0, 4, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 20, 0, 0, 0, 24, 0, 0, 0, 0, 0, 0, 0, 32, 0, 0, 0, 0, 0, 0, 0, 13, 0, 0, 0, 0, 0, 0, 0, 48, 0, 0, 0, 7, 0, 0, 0, 56, 0, 0, 0, 0, 0, 0, 0, 21, 0, 0, 0, 68, 0, 0, 0, 72, 0, 0, 0, 0, 0, 0, 0, 80, 0, 0, 0, 84, 0, 0, 0, 19, 0, 0, 0, 0, 0, 0, 0, 96, 0, 0, 0]

cp's OEIS Frontend

A087263 a(n) is the least initial value of a 3x+1 trajectory in which n is the largest (peak) term or a(n) = 0 if n cannot be a peak value (i.e., when n = 2k+1, n = 4k+2, n = 16k+12, etc.).

Table of values

List of values

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

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

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