A353905 - cp's OEIS frontend

A353905 a(1) = 1; for n > 1, a(n) = smallest positive number that has not appeared that has a common factor with a(n-1) + the smallest unseen positive number.

n	a(n)
1	1
2	3
3	5
4	7
5	6
6	2
7	4
8	8
9	17
10	10
11	19
12	12
13	9
14	14
15	15
16	13
17	16
18	18
19	29
20	20
21	31
22	21
23	22
24	11
25	24
26	47
27	25
28	26
29	28
30	27
31	30
32	53
33	32
34	33
35	34
36	36
37	59
38	38
39	61
40	35
41	40
42	39
43	42
44	45
45	44
46	67
47	46
48	23
49	48
50	50
51	51
52	52
53	89
54	49
55	43
56	54
57	56
58	57
59	58
60	55
61	60
62	97
63	62
64	63
65	64
66	101
67	66
68	103
69	65
70	68
71	69
72	70
73	107
74	72
75	109

[1, 3, 5, 7, 6, 2, 4, 8, 17, 10, 19, 12, 9, 14, 15, 13, 16, 18, 29, 20, 31, 21, 22, 11, 24, 47, 25, 26, 28, 27, 30, 53, 32, 33, 34, 36, 59, 38, 61, 35, 40, 39, 42, 45, 44, 67, 46, 23, 48, 50, 51, 52, 89, 49, 43, 54, 56, 57, 58, 55, 60, 97, 62, 63, 64, 101, 66, 103, 65, 68, 69, 70, 107, 72, 109]

cp's OEIS Frontend

A353905 a(1) = 1; for n > 1, a(n) = smallest positive number that has not appeared that has a common factor with a(n-1) + the smallest unseen positive number.

Table of values

List of values

n	a(n)
1	1
2	3
3	5
4	7
5	6
6	2
7	4
8	8
9	17
10	10
11	19
12	12
13	9
14	14
15	15
16	13
17	16
18	18
19	29
20	20
21	31
22	21
23	22
24	11
25	24
26	47
27	25
28	26
29	28
30	27
31	30
32	53
33	32
34	33
35	34
36	36
37	59
38	38
39	61
40	35
41	40
42	39
43	42
44	45
45	44
46	67
47	46
48	23
49	48
50	50
51	51
52	52
53	89
54	49
55	43
56	54
57	56
58	57
59	58
60	55
61	60
62	97
63	62
64	63
65	64
66	101
67	66
68	103
69	65
70	68
71	69
72	70
73	107
74	72
75	109

n	a(n)
1	1
2	3
3	5
4	7
5	6
6	2
7	4
8	8
9	17
10	10
11	19
12	12
13	9
14	14
15	15
16	13
17	16
18	18
19	29
20	20
21	31
22	21
23	22
24	11
25	24
26	47
27	25
28	26
29	28
30	27
31	30
32	53
33	32
34	33
35	34
36	36
37	59
38	38
39	61
40	35
41	40
42	39
43	42
44	45
45	44
46	67
47	46
48	23
49	48
50	50
51	51
52	52
53	89
54	49
55	43
56	54
57	56
58	57
59	58
60	55
61	60
62	97
63	62
64	63
65	64
66	101
67	66
68	103
69	65
70	68
71	69
72	70
73	107
74	72
75	109

n	a(n)
1	1
2	3
3	5
4	7
5	6
6	2
7	4
8	8
9	17
10	10
11	19
12	12
13	9
14	14
15	15
16	13
17	16
18	18
19	29
20	20
21	31
22	21
23	22
24	11
25	24
26	47
27	25
28	26
29	28
30	27
31	30
32	53
33	32
34	33
35	34
36	36
37	59
38	38
39	61
40	35
41	40
42	39
43	42
44	45
45	44
46	67
47	46
48	23
49	48
50	50
51	51
52	52
53	89
54	49
55	43
56	54
57	56
58	57
59	58
60	55
61	60
62	97
63	62
64	63
65	64
66	101
67	66
68	103
69	65
70	68
71	69
72	70
73	107
74	72
75	109