A335683 - cp's OEIS frontend

A335683 Array read by antidiagonals: T(n,k) (n >= 1, k >= 1) = Sum_{i=1..n, j=1..k, gcd(i,j)=2} (n+1-i)*(k+1-j).

n	a(n)
1	0
2	0
3	0
4	0
5	1
6	0
7	0
8	2
9	2
10	0
11	0
12	4
13	4
14	4
15	0
16	0
17	6
18	8
19	8
20	6
21	0
22	0
23	9
24	12
25	15
26	12
27	9
28	0
29	0
30	12
31	18
32	22
33	22
34	18
35	12
36	0
37	0
38	16
39	24
40	33
41	32
42	33
43	24
44	16
45	0
46	0
47	20
48	32
49	44
50	48
51	48
52	44
53	32
54	20
55	0
56	0
57	25
58	40
59	58
60	64
61	71
62	64
63	58
64	40
65	25
66	0
67	0
68	30
69	50
70	72
71	84
72	94
73	94
74	84
75	72
76	50
77	30
78	0

[0, 0, 0, 0, 1, 0, 0, 2, 2, 0, 0, 4, 4, 4, 0, 0, 6, 8, 8, 6, 0, 0, 9, 12, 15, 12, 9, 0, 0, 12, 18, 22, 22, 18, 12, 0, 0, 16, 24, 33, 32, 33, 24, 16, 0, 0, 20, 32, 44, 48, 48, 44, 32, 20, 0, 0, 25, 40, 58, 64, 71, 64, 58, 40, 25, 0, 0, 30, 50, 72, 84, 94, 94, 84, 72, 50, 30, 0]

cp's OEIS Frontend

A335683 Array read by antidiagonals: T(n,k) (n >= 1, k >= 1) = Sum_{i=1..n, j=1..k, gcd(i,j)=2} (n+1-i)*(k+1-j).

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	0
5	1
6	0
7	0
8	2
9	2
10	0
11	0
12	4
13	4
14	4
15	0
16	0
17	6
18	8
19	8
20	6
21	0
22	0
23	9
24	12
25	15
26	12
27	9
28	0
29	0
30	12
31	18
32	22
33	22
34	18
35	12
36	0
37	0
38	16
39	24
40	33
41	32
42	33
43	24
44	16
45	0
46	0
47	20
48	32
49	44
50	48
51	48
52	44
53	32
54	20
55	0
56	0
57	25
58	40
59	58
60	64
61	71
62	64
63	58
64	40
65	25
66	0
67	0
68	30
69	50
70	72
71	84
72	94
73	94
74	84
75	72
76	50
77	30
78	0

n	a(n)
1	0
2	0
3	0
4	0
5	1
6	0
7	0
8	2
9	2
10	0
11	0
12	4
13	4
14	4
15	0
16	0
17	6
18	8
19	8
20	6
21	0
22	0
23	9
24	12
25	15
26	12
27	9
28	0
29	0
30	12
31	18
32	22
33	22
34	18
35	12
36	0
37	0
38	16
39	24
40	33
41	32
42	33
43	24
44	16
45	0
46	0
47	20
48	32
49	44
50	48
51	48
52	44
53	32
54	20
55	0
56	0
57	25
58	40
59	58
60	64
61	71
62	64
63	58
64	40
65	25
66	0
67	0
68	30
69	50
70	72
71	84
72	94
73	94
74	84
75	72
76	50
77	30
78	0

n	a(n)
1	0
2	0
3	0
4	0
5	1
6	0
7	0
8	2
9	2
10	0
11	0
12	4
13	4
14	4
15	0
16	0
17	6
18	8
19	8
20	6
21	0
22	0
23	9
24	12
25	15
26	12
27	9
28	0
29	0
30	12
31	18
32	22
33	22
34	18
35	12
36	0
37	0
38	16
39	24
40	33
41	32
42	33
43	24
44	16
45	0
46	0
47	20
48	32
49	44
50	48
51	48
52	44
53	32
54	20
55	0
56	0
57	25
58	40
59	58
60	64
61	71
62	64
63	58
64	40
65	25
66	0
67	0
68	30
69	50
70	72
71	84
72	94
73	94
74	84
75	72
76	50
77	30
78	0