A060992 - cp's OEIS frontend

A060992 a(n) = Sum_{gcd(i,j) | 0 < i <= j < n and i+j = n}.

n	a(n)
1	0
2	1
3	1
4	3
5	2
6	6
7	3
8	8
9	6
10	11
11	5
12	17
13	6
14	16
15	15
16	20
17	8
18	27
19	9
20	31
21	22
22	26
23	11
24	44
25	20
26	31
27	27
28	45
29	14
30	60
31	15
32	48
33	36
34	41
35	41
36	75
37	18
38	46
39	43
40	80
41	20
42	87
43	21
44	73
45	72
46	56
47	23
48	108
49	42
50	85
51	57
52	87
53	26
54	108
55	67
56	116
57	64
58	71
59	29
60	165
61	30
62	76

[0, 1, 1, 3, 2, 6, 3, 8, 6, 11, 5, 17, 6, 16, 15, 20, 8, 27, 9, 31, 22, 26, 11, 44, 20, 31, 27, 45, 14, 60, 15, 48, 36, 41, 41, 75, 18, 46, 43, 80, 20, 87, 21, 73, 72, 56, 23, 108, 42, 85, 57, 87, 26, 108, 67, 116, 64, 71, 29, 165, 30, 76]

cp's OEIS Frontend

A060992 a(n) = Sum_{gcd(i,j) | 0 < i <= j < n and i+j = n}.

Table of values

List of values

n	a(n)
1	0
2	1
3	1
4	3
5	2
6	6
7	3
8	8
9	6
10	11
11	5
12	17
13	6
14	16
15	15
16	20
17	8
18	27
19	9
20	31
21	22
22	26
23	11
24	44
25	20
26	31
27	27
28	45
29	14
30	60
31	15
32	48
33	36
34	41
35	41
36	75
37	18
38	46
39	43
40	80
41	20
42	87
43	21
44	73
45	72
46	56
47	23
48	108
49	42
50	85
51	57
52	87
53	26
54	108
55	67
56	116
57	64
58	71
59	29
60	165
61	30
62	76

n	a(n)
1	0
2	1
3	1
4	3
5	2
6	6
7	3
8	8
9	6
10	11
11	5
12	17
13	6
14	16
15	15
16	20
17	8
18	27
19	9
20	31
21	22
22	26
23	11
24	44
25	20
26	31
27	27
28	45
29	14
30	60
31	15
32	48
33	36
34	41
35	41
36	75
37	18
38	46
39	43
40	80
41	20
42	87
43	21
44	73
45	72
46	56
47	23
48	108
49	42
50	85
51	57
52	87
53	26
54	108
55	67
56	116
57	64
58	71
59	29
60	165
61	30
62	76

n	a(n)
1	0
2	1
3	1
4	3
5	2
6	6
7	3
8	8
9	6
10	11
11	5
12	17
13	6
14	16
15	15
16	20
17	8
18	27
19	9
20	31
21	22
22	26
23	11
24	44
25	20
26	31
27	27
28	45
29	14
30	60
31	15
32	48
33	36
34	41
35	41
36	75
37	18
38	46
39	43
40	80
41	20
42	87
43	21
44	73
45	72
46	56
47	23
48	108
49	42
50	85
51	57
52	87
53	26
54	108
55	67
56	116
57	64
58	71
59	29
60	165
61	30
62	76