A121998 - cp's OEIS frontend

A121998 Table, n-th row gives numbers between 1 and n that have a common factor with n.

n	a(n)
2	2
3	3
4	2
5	4
6	5
7	2
8	3
9	4
10	6
11	7
12	2
13	4
14	6
15	8
16	3
17	6
18	9
19	2
20	4
21	5
22	6
23	8
24	10
25	11
26	2
27	3
28	4
29	6
30	8
31	9
32	10
33	12
34	13
35	2
36	4
37	6
38	7
39	8
40	10
41	12
42	14
43	3
44	5
45	6
46	9
47	10
48	12
49	15
50	2
51	4
52	6
53	8
54	10
55	12
56	14
57	16
58	17
59	2
60	3
61	4
62	6
63	8
64	9
65	10
66	12
67	14
68	15
69	16
70	18
71	19
72	2
73	4
74	5
75	6
76	8
77	10
78	12
79	14
80	15
81	16
82	18
83	20
84	3
85	6
86	7
87	9
88	12
89	14
90	15

[2, 3, 2, 4, 5, 2, 3, 4, 6, 7, 2, 4, 6, 8, 3, 6, 9, 2, 4, 5, 6, 8, 10, 11, 2, 3, 4, 6, 8, 9, 10, 12, 13, 2, 4, 6, 7, 8, 10, 12, 14, 3, 5, 6, 9, 10, 12, 15, 2, 4, 6, 8, 10, 12, 14, 16, 17, 2, 3, 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 19, 2, 4, 5, 6, 8, 10, 12, 14, 15, 16, 18, 20, 3, 6, 7, 9, 12, 14, 15]

cp's OEIS Frontend

A121998 Table, n-th row gives numbers between 1 and n that have a common factor with n.

Table of values

List of values

n	a(n)
2	2
3	3
4	2
5	4
6	5
7	2
8	3
9	4
10	6
11	7
12	2
13	4
14	6
15	8
16	3
17	6
18	9
19	2
20	4
21	5
22	6
23	8
24	10
25	11
26	2
27	3
28	4
29	6
30	8
31	9
32	10
33	12
34	13
35	2
36	4
37	6
38	7
39	8
40	10
41	12
42	14
43	3
44	5
45	6
46	9
47	10
48	12
49	15
50	2
51	4
52	6
53	8
54	10
55	12
56	14
57	16
58	17
59	2
60	3
61	4
62	6
63	8
64	9
65	10
66	12
67	14
68	15
69	16
70	18
71	19
72	2
73	4
74	5
75	6
76	8
77	10
78	12
79	14
80	15
81	16
82	18
83	20
84	3
85	6
86	7
87	9
88	12
89	14
90	15

n	a(n)
2	2
3	3
4	2
5	4
6	5
7	2
8	3
9	4
10	6
11	7
12	2
13	4
14	6
15	8
16	3
17	6
18	9
19	2
20	4
21	5
22	6
23	8
24	10
25	11
26	2
27	3
28	4
29	6
30	8
31	9
32	10
33	12
34	13
35	2
36	4
37	6
38	7
39	8
40	10
41	12
42	14
43	3
44	5
45	6
46	9
47	10
48	12
49	15
50	2
51	4
52	6
53	8
54	10
55	12
56	14
57	16
58	17
59	2
60	3
61	4
62	6
63	8
64	9
65	10
66	12
67	14
68	15
69	16
70	18
71	19
72	2
73	4
74	5
75	6
76	8
77	10
78	12
79	14
80	15
81	16
82	18
83	20
84	3
85	6
86	7
87	9
88	12
89	14
90	15

n	a(n)
2	2
3	3
4	2
5	4
6	5
7	2
8	3
9	4
10	6
11	7
12	2
13	4
14	6
15	8
16	3
17	6
18	9
19	2
20	4
21	5
22	6
23	8
24	10
25	11
26	2
27	3
28	4
29	6
30	8
31	9
32	10
33	12
34	13
35	2
36	4
37	6
38	7
39	8
40	10
41	12
42	14
43	3
44	5
45	6
46	9
47	10
48	12
49	15
50	2
51	4
52	6
53	8
54	10
55	12
56	14
57	16
58	17
59	2
60	3
61	4
62	6
63	8
64	9
65	10
66	12
67	14
68	15
69	16
70	18
71	19
72	2
73	4
74	5
75	6
76	8
77	10
78	12
79	14
80	15
81	16
82	18
83	20
84	3
85	6
86	7
87	9
88	12
89	14
90	15