A308021 - cp's OEIS frontend

A308021 Start at n=1. Fill in a(n) with a value d > 0 not used earlier such that n-d or n+d is the smallest possible index not visited earlier, then continue with that index.

n	a(n)
1	1
2	2
3	5
4	3
5	7
6	10
7	4
8	6
9	12
10	15
11	17
12	8
13	20
14	9
15	22
16	11
17	25
18	27
19	29
20	14
21	13
22	33
23	35
24	37
25	16
26	40
27	18
28	19
29	42
30	45
31	47
32	49
33	21
34	24
35	52
36	55
37	23
38	58
39	61
40	62
41	30
42	26
43	65
44	66
45	28
46	68
47	34
48	31
49	71
50	74
51	76
52	79
53	81
54	39
55	32
56	83
57	86
58	36
59	89
60	43
61	38
62	91
63	93
64	96
65	99
66	41
67	101
68	50
69	103
70	106
71	44
72	108
73	54
74	111
75	46
76	113
77	117
78	48
79	57
80	118
81	51
82	120
83	123

[1, 2, 5, 3, 7, 10, 4, 6, 12, 15, 17, 8, 20, 9, 22, 11, 25, 27, 29, 14, 13, 33, 35, 37, 16, 40, 18, 19, 42, 45, 47, 49, 21, 24, 52, 55, 23, 58, 61, 62, 30, 26, 65, 66, 28, 68, 34, 31, 71, 74, 76, 79, 81, 39, 32, 83, 86, 36, 89, 43, 38, 91, 93, 96, 99, 41, 101, 50, 103, 106, 44, 108, 54, 111, 46, 113, 117, 48, 57, 118, 51, 120, 123]

cp's OEIS Frontend

A308021 Start at n=1. Fill in a(n) with a value d > 0 not used earlier such that n-d or n+d is the smallest possible index not visited earlier, then continue with that index.

Table of values

List of values

n	a(n)
1	1
2	2
3	5
4	3
5	7
6	10
7	4
8	6
9	12
10	15
11	17
12	8
13	20
14	9
15	22
16	11
17	25
18	27
19	29
20	14
21	13
22	33
23	35
24	37
25	16
26	40
27	18
28	19
29	42
30	45
31	47
32	49
33	21
34	24
35	52
36	55
37	23
38	58
39	61
40	62
41	30
42	26
43	65
44	66
45	28
46	68
47	34
48	31
49	71
50	74
51	76
52	79
53	81
54	39
55	32
56	83
57	86
58	36
59	89
60	43
61	38
62	91
63	93
64	96
65	99
66	41
67	101
68	50
69	103
70	106
71	44
72	108
73	54
74	111
75	46
76	113
77	117
78	48
79	57
80	118
81	51
82	120
83	123

n	a(n)
1	1
2	2
3	5
4	3
5	7
6	10
7	4
8	6
9	12
10	15
11	17
12	8
13	20
14	9
15	22
16	11
17	25
18	27
19	29
20	14
21	13
22	33
23	35
24	37
25	16
26	40
27	18
28	19
29	42
30	45
31	47
32	49
33	21
34	24
35	52
36	55
37	23
38	58
39	61
40	62
41	30
42	26
43	65
44	66
45	28
46	68
47	34
48	31
49	71
50	74
51	76
52	79
53	81
54	39
55	32
56	83
57	86
58	36
59	89
60	43
61	38
62	91
63	93
64	96
65	99
66	41
67	101
68	50
69	103
70	106
71	44
72	108
73	54
74	111
75	46
76	113
77	117
78	48
79	57
80	118
81	51
82	120
83	123

n	a(n)
1	1
2	2
3	5
4	3
5	7
6	10
7	4
8	6
9	12
10	15
11	17
12	8
13	20
14	9
15	22
16	11
17	25
18	27
19	29
20	14
21	13
22	33
23	35
24	37
25	16
26	40
27	18
28	19
29	42
30	45
31	47
32	49
33	21
34	24
35	52
36	55
37	23
38	58
39	61
40	62
41	30
42	26
43	65
44	66
45	28
46	68
47	34
48	31
49	71
50	74
51	76
52	79
53	81
54	39
55	32
56	83
57	86
58	36
59	89
60	43
61	38
62	91
63	93
64	96
65	99
66	41
67	101
68	50
69	103
70	106
71	44
72	108
73	54
74	111
75	46
76	113
77	117
78	48
79	57
80	118
81	51
82	120
83	123