A262922 - cp's OEIS frontend

A262922 a(1)=1; for n>1, a(n) = a(n-1) + n + 2 if a(n-1) and n are coprime, otherwise a(n) = a(n-1)/gcd(a(n-1),n).

n	a(n)
1	1
2	5
3	10
4	5
5	1
6	9
7	18
8	9
9	1
10	13
11	26
12	13
13	1
14	17
15	34
16	17
17	1
18	21
19	42
20	21
21	1
22	25
23	50
24	25
25	1
26	29
27	58
28	29
29	1
30	33
31	66
32	33
33	1
34	37
35	74
36	37
37	1
38	41
39	82
40	41
41	1
42	45
43	90
44	45
45	1
46	49
47	98
48	49
49	1
50	53
51	106
52	53
53	1
54	57
55	114
56	57
57	1
58	61
59	122
60	61
61	1
62	65
63	130
64	65
65	1
66	69
67	138
68	69
69	1
70	73
71	146
72	73
73	1
74	77
75	154
76	77
77	1
78	81
79	162

[1, 5, 10, 5, 1, 9, 18, 9, 1, 13, 26, 13, 1, 17, 34, 17, 1, 21, 42, 21, 1, 25, 50, 25, 1, 29, 58, 29, 1, 33, 66, 33, 1, 37, 74, 37, 1, 41, 82, 41, 1, 45, 90, 45, 1, 49, 98, 49, 1, 53, 106, 53, 1, 57, 114, 57, 1, 61, 122, 61, 1, 65, 130, 65, 1, 69, 138, 69, 1, 73, 146, 73, 1, 77, 154, 77, 1, 81, 162]

cp's OEIS Frontend

A262922 a(1)=1; for n>1, a(n) = a(n-1) + n + 2 if a(n-1) and n are coprime, otherwise a(n) = a(n-1)/gcd(a(n-1),n).

Table of values

List of values

n	a(n)
1	1
2	5
3	10
4	5
5	1
6	9
7	18
8	9
9	1
10	13
11	26
12	13
13	1
14	17
15	34
16	17
17	1
18	21
19	42
20	21
21	1
22	25
23	50
24	25
25	1
26	29
27	58
28	29
29	1
30	33
31	66
32	33
33	1
34	37
35	74
36	37
37	1
38	41
39	82
40	41
41	1
42	45
43	90
44	45
45	1
46	49
47	98
48	49
49	1
50	53
51	106
52	53
53	1
54	57
55	114
56	57
57	1
58	61
59	122
60	61
61	1
62	65
63	130
64	65
65	1
66	69
67	138
68	69
69	1
70	73
71	146
72	73
73	1
74	77
75	154
76	77
77	1
78	81
79	162

n	a(n)
1	1
2	5
3	10
4	5
5	1
6	9
7	18
8	9
9	1
10	13
11	26
12	13
13	1
14	17
15	34
16	17
17	1
18	21
19	42
20	21
21	1
22	25
23	50
24	25
25	1
26	29
27	58
28	29
29	1
30	33
31	66
32	33
33	1
34	37
35	74
36	37
37	1
38	41
39	82
40	41
41	1
42	45
43	90
44	45
45	1
46	49
47	98
48	49
49	1
50	53
51	106
52	53
53	1
54	57
55	114
56	57
57	1
58	61
59	122
60	61
61	1
62	65
63	130
64	65
65	1
66	69
67	138
68	69
69	1
70	73
71	146
72	73
73	1
74	77
75	154
76	77
77	1
78	81
79	162

n	a(n)
1	1
2	5
3	10
4	5
5	1
6	9
7	18
8	9
9	1
10	13
11	26
12	13
13	1
14	17
15	34
16	17
17	1
18	21
19	42
20	21
21	1
22	25
23	50
24	25
25	1
26	29
27	58
28	29
29	1
30	33
31	66
32	33
33	1
34	37
35	74
36	37
37	1
38	41
39	82
40	41
41	1
42	45
43	90
44	45
45	1
46	49
47	98
48	49
49	1
50	53
51	106
52	53
53	1
54	57
55	114
56	57
57	1
58	61
59	122
60	61
61	1
62	65
63	130
64	65
65	1
66	69
67	138
68	69
69	1
70	73
71	146
72	73
73	1
74	77
75	154
76	77
77	1
78	81
79	162