A325909 - cp's OEIS frontend

A325909 Lexicographically earliest sequence of distinct positive terms such that for any n > 0, n divides Sum_{k = 1..n} (-1)^k * a(k).

n	a(n)
1	1
2	3
3	2
4	4
5	9
6	5
7	7
8	15
9	8
10	10
11	21
12	11
13	13
14	27
15	14
16	16
17	33
18	17
19	19
20	39
21	20
22	22
23	45
24	23
25	25
26	51
27	26
28	28
29	57
30	29
31	31
32	63
33	32
34	34
35	69
36	35
37	37
38	75
39	38
40	40
41	81
42	41
43	43
44	87
45	44
46	46
47	93
48	47
49	49
50	99
51	50
52	52
53	105
54	53
55	55
56	111
57	56
58	58
59	117
60	59
61	61
62	123
63	62
64	64
65	129
66	65

[1, 3, 2, 4, 9, 5, 7, 15, 8, 10, 21, 11, 13, 27, 14, 16, 33, 17, 19, 39, 20, 22, 45, 23, 25, 51, 26, 28, 57, 29, 31, 63, 32, 34, 69, 35, 37, 75, 38, 40, 81, 41, 43, 87, 44, 46, 93, 47, 49, 99, 50, 52, 105, 53, 55, 111, 56, 58, 117, 59, 61, 123, 62, 64, 129, 65]

cp's OEIS Frontend

A325909 Lexicographically earliest sequence of distinct positive terms such that for any n > 0, n divides Sum_{k = 1..n} (-1)^k * a(k).

Table of values

List of values

n	a(n)
1	1
2	3
3	2
4	4
5	9
6	5
7	7
8	15
9	8
10	10
11	21
12	11
13	13
14	27
15	14
16	16
17	33
18	17
19	19
20	39
21	20
22	22
23	45
24	23
25	25
26	51
27	26
28	28
29	57
30	29
31	31
32	63
33	32
34	34
35	69
36	35
37	37
38	75
39	38
40	40
41	81
42	41
43	43
44	87
45	44
46	46
47	93
48	47
49	49
50	99
51	50
52	52
53	105
54	53
55	55
56	111
57	56
58	58
59	117
60	59
61	61
62	123
63	62
64	64
65	129
66	65

n	a(n)
1	1
2	3
3	2
4	4
5	9
6	5
7	7
8	15
9	8
10	10
11	21
12	11
13	13
14	27
15	14
16	16
17	33
18	17
19	19
20	39
21	20
22	22
23	45
24	23
25	25
26	51
27	26
28	28
29	57
30	29
31	31
32	63
33	32
34	34
35	69
36	35
37	37
38	75
39	38
40	40
41	81
42	41
43	43
44	87
45	44
46	46
47	93
48	47
49	49
50	99
51	50
52	52
53	105
54	53
55	55
56	111
57	56
58	58
59	117
60	59
61	61
62	123
63	62
64	64
65	129
66	65

n	a(n)
1	1
2	3
3	2
4	4
5	9
6	5
7	7
8	15
9	8
10	10
11	21
12	11
13	13
14	27
15	14
16	16
17	33
18	17
19	19
20	39
21	20
22	22
23	45
24	23
25	25
26	51
27	26
28	28
29	57
30	29
31	31
32	63
33	32
34	34
35	69
36	35
37	37
38	75
39	38
40	40
41	81
42	41
43	43
44	87
45	44
46	46
47	93
48	47
49	49
50	99
51	50
52	52
53	105
54	53
55	55
56	111
57	56
58	58
59	117
60	59
61	61
62	123
63	62
64	64
65	129
66	65