A356886 - cp's OEIS frontend

A356886 Write n as 2^m - k, where 2^m is the least power of 2 such that 2^m >= n, and k is a number in the range 0 <= k < 2^(m-1) - 1. Then for n such that k=0, a(n)=n, and for n such that k > 0, a(n) is the smallest odd prime multiple of a(k) that is not already a term.

n	a(n)
1	1
2	2
3	3
4	4
5	9
6	6
7	5
8	8
9	15
10	18
11	27
12	12
13	21
14	10
15	7
16	16
17	35
18	30
19	63
20	36
21	81
22	54
23	45
24	24
25	25
26	42
27	99
28	20
29	33
30	14
31	11
32	32
33	55
34	70
35	165
36	60
37	297
38	126
39	75
40	72
41	135
42	162
43	243
44	108
45	189
46	90
47	105
48	48
49	49
50	50
51	147
52	84
53	351
54	198
55	195
56	40
57	65
58	66
59	117
60	28
61	39
62	22
63	13
64	64
65	91

[1, 2, 3, 4, 9, 6, 5, 8, 15, 18, 27, 12, 21, 10, 7, 16, 35, 30, 63, 36, 81, 54, 45, 24, 25, 42, 99, 20, 33, 14, 11, 32, 55, 70, 165, 60, 297, 126, 75, 72, 135, 162, 243, 108, 189, 90, 105, 48, 49, 50, 147, 84, 351, 198, 195, 40, 65, 66, 117, 28, 39, 22, 13, 64, 91]

cp's OEIS Frontend

A356886 Write n as 2^m - k, where 2^m is the least power of 2 such that 2^m >= n, and k is a number in the range 0 <= k < 2^(m-1) - 1. Then for n such that k=0, a(n)=n, and for n such that k > 0, a(n) is the smallest odd prime multiple of a(k) that is not already a term.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	9
6	6
7	5
8	8
9	15
10	18
11	27
12	12
13	21
14	10
15	7
16	16
17	35
18	30
19	63
20	36
21	81
22	54
23	45
24	24
25	25
26	42
27	99
28	20
29	33
30	14
31	11
32	32
33	55
34	70
35	165
36	60
37	297
38	126
39	75
40	72
41	135
42	162
43	243
44	108
45	189
46	90
47	105
48	48
49	49
50	50
51	147
52	84
53	351
54	198
55	195
56	40
57	65
58	66
59	117
60	28
61	39
62	22
63	13
64	64
65	91

n	a(n)
1	1
2	2
3	3
4	4
5	9
6	6
7	5
8	8
9	15
10	18
11	27
12	12
13	21
14	10
15	7
16	16
17	35
18	30
19	63
20	36
21	81
22	54
23	45
24	24
25	25
26	42
27	99
28	20
29	33
30	14
31	11
32	32
33	55
34	70
35	165
36	60
37	297
38	126
39	75
40	72
41	135
42	162
43	243
44	108
45	189
46	90
47	105
48	48
49	49
50	50
51	147
52	84
53	351
54	198
55	195
56	40
57	65
58	66
59	117
60	28
61	39
62	22
63	13
64	64
65	91

n	a(n)
1	1
2	2
3	3
4	4
5	9
6	6
7	5
8	8
9	15
10	18
11	27
12	12
13	21
14	10
15	7
16	16
17	35
18	30
19	63
20	36
21	81
22	54
23	45
24	24
25	25
26	42
27	99
28	20
29	33
30	14
31	11
32	32
33	55
34	70
35	165
36	60
37	297
38	126
39	75
40	72
41	135
42	162
43	243
44	108
45	189
46	90
47	105
48	48
49	49
50	50
51	147
52	84
53	351
54	198
55	195
56	40
57	65
58	66
59	117
60	28
61	39
62	22
63	13
64	64
65	91