A169957 - cp's OEIS frontend

A169957 a(1) = 1, then a(n) is the smallest number such that a(a(n)) = 2n+1.

n	a(n)
1	1
2	3
3	5
4	6
5	7
6	9
7	11
8	10
9	13
10	17
11	15
12	14
13	19
14	25
15	23
16	18
17	21
18	33
19	27
20	22
21	35
22	41
23	31
24	26
25	29
26	49
27	39
28	30
29	51
30	57
31	47
32	34
33	37
34	65
35	43
36	38
37	67
38	73
39	55
40	42
41	45
42	81
43	71
44	46
45	83
46	89
47	63
48	50
49	53
50	97
51	59
52	54
53	99
54	105
55	79
56	58
57	61
58	113
59	103
60	62
61	115

[1, 3, 5, 6, 7, 9, 11, 10, 13, 17, 15, 14, 19, 25, 23, 18, 21, 33, 27, 22, 35, 41, 31, 26, 29, 49, 39, 30, 51, 57, 47, 34, 37, 65, 43, 38, 67, 73, 55, 42, 45, 81, 71, 46, 83, 89, 63, 50, 53, 97, 59, 54, 99, 105, 79, 58, 61, 113, 103, 62, 115]

cp's OEIS Frontend

A169957 a(1) = 1, then a(n) is the smallest number such that a(a(n)) = 2n+1.

Table of values

List of values

n	a(n)
1	1
2	3
3	5
4	6
5	7
6	9
7	11
8	10
9	13
10	17
11	15
12	14
13	19
14	25
15	23
16	18
17	21
18	33
19	27
20	22
21	35
22	41
23	31
24	26
25	29
26	49
27	39
28	30
29	51
30	57
31	47
32	34
33	37
34	65
35	43
36	38
37	67
38	73
39	55
40	42
41	45
42	81
43	71
44	46
45	83
46	89
47	63
48	50
49	53
50	97
51	59
52	54
53	99
54	105
55	79
56	58
57	61
58	113
59	103
60	62
61	115

n	a(n)
1	1
2	3
3	5
4	6
5	7
6	9
7	11
8	10
9	13
10	17
11	15
12	14
13	19
14	25
15	23
16	18
17	21
18	33
19	27
20	22
21	35
22	41
23	31
24	26
25	29
26	49
27	39
28	30
29	51
30	57
31	47
32	34
33	37
34	65
35	43
36	38
37	67
38	73
39	55
40	42
41	45
42	81
43	71
44	46
45	83
46	89
47	63
48	50
49	53
50	97
51	59
52	54
53	99
54	105
55	79
56	58
57	61
58	113
59	103
60	62
61	115

n	a(n)
1	1
2	3
3	5
4	6
5	7
6	9
7	11
8	10
9	13
10	17
11	15
12	14
13	19
14	25
15	23
16	18
17	21
18	33
19	27
20	22
21	35
22	41
23	31
24	26
25	29
26	49
27	39
28	30
29	51
30	57
31	47
32	34
33	37
34	65
35	43
36	38
37	67
38	73
39	55
40	42
41	45
42	81
43	71
44	46
45	83
46	89
47	63
48	50
49	53
50	97
51	59
52	54
53	99
54	105
55	79
56	58
57	61
58	113
59	103
60	62
61	115