A268642 - cp's OEIS frontend

A268642 Seelmann's sequence: a(1) = 1; thereafter a(n + 1) = ceiling(a(n)/2) unless this is already in the sequence, in which case a(n + 1) = 3*a(n).

n	a(n)
1	1
2	3
3	2
4	6
5	18
6	9
7	5
8	15
9	8
10	4
11	12
12	36
13	108
14	54
15	27
16	14
17	7
18	21
19	11
20	33
21	17
22	51
23	26
24	13
25	39
26	20
27	10
28	30
29	90
30	45
31	23
32	69
33	35
34	105
35	53
36	159
37	80
38	40
39	120
40	60
41	180
42	540
43	270
44	135
45	68
46	34
47	102
48	306
49	153
50	77
51	231
52	116
53	58
54	29
55	87
56	44
57	22
58	66
59	198
60	99
61	50
62	25
63	75
64	38

[1, 3, 2, 6, 18, 9, 5, 15, 8, 4, 12, 36, 108, 54, 27, 14, 7, 21, 11, 33, 17, 51, 26, 13, 39, 20, 10, 30, 90, 45, 23, 69, 35, 105, 53, 159, 80, 40, 120, 60, 180, 540, 270, 135, 68, 34, 102, 306, 153, 77, 231, 116, 58, 29, 87, 44, 22, 66, 198, 99, 50, 25, 75, 38]

cp's OEIS Frontend

A268642 Seelmann's sequence: a(1) = 1; thereafter a(n + 1) = ceiling(a(n)/2) unless this is already in the sequence, in which case a(n + 1) = 3*a(n).

Table of values

List of values

n	a(n)
1	1
2	3
3	2
4	6
5	18
6	9
7	5
8	15
9	8
10	4
11	12
12	36
13	108
14	54
15	27
16	14
17	7
18	21
19	11
20	33
21	17
22	51
23	26
24	13
25	39
26	20
27	10
28	30
29	90
30	45
31	23
32	69
33	35
34	105
35	53
36	159
37	80
38	40
39	120
40	60
41	180
42	540
43	270
44	135
45	68
46	34
47	102
48	306
49	153
50	77
51	231
52	116
53	58
54	29
55	87
56	44
57	22
58	66
59	198
60	99
61	50
62	25
63	75
64	38

n	a(n)
1	1
2	3
3	2
4	6
5	18
6	9
7	5
8	15
9	8
10	4
11	12
12	36
13	108
14	54
15	27
16	14
17	7
18	21
19	11
20	33
21	17
22	51
23	26
24	13
25	39
26	20
27	10
28	30
29	90
30	45
31	23
32	69
33	35
34	105
35	53
36	159
37	80
38	40
39	120
40	60
41	180
42	540
43	270
44	135
45	68
46	34
47	102
48	306
49	153
50	77
51	231
52	116
53	58
54	29
55	87
56	44
57	22
58	66
59	198
60	99
61	50
62	25
63	75
64	38

n	a(n)
1	1
2	3
3	2
4	6
5	18
6	9
7	5
8	15
9	8
10	4
11	12
12	36
13	108
14	54
15	27
16	14
17	7
18	21
19	11
20	33
21	17
22	51
23	26
24	13
25	39
26	20
27	10
28	30
29	90
30	45
31	23
32	69
33	35
34	105
35	53
36	159
37	80
38	40
39	120
40	60
41	180
42	540
43	270
44	135
45	68
46	34
47	102
48	306
49	153
50	77
51	231
52	116
53	58
54	29
55	87
56	44
57	22
58	66
59	198
60	99
61	50
62	25
63	75
64	38