A216624 - cp's OEIS frontend

A216624 Square array read by antidiagonals, T(n,k) = sum_{c|n,d|k} gcd(c,d) for n>=1, k>=1.

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

[1, 2, 2, 2, 5, 2, 3, 4, 4, 3, 2, 8, 6, 8, 2, 4, 4, 6, 6, 4, 4, 2, 10, 4, 15, 4, 10, 2, 4, 4, 12, 6, 6, 12, 4, 4, 3, 11, 4, 16, 8, 16, 4, 11, 3, 4, 6, 8, 6, 8, 8, 6, 8, 6, 4, 2, 10, 10, 22, 4, 30, 4, 22, 10, 10, 2, 6, 4, 8, 9, 8, 8, 8, 8, 9, 8, 4, 6]

cp's OEIS Frontend

A216624 Square array read by antidiagonals, T(n,k) = sum_{c|n,d|k} gcd(c,d) for n>=1, k>=1.

Table of values

List of values

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

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

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