A220691 - cp's OEIS frontend

A220691 Table A(i,j) read by antidiagonals in order A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), ..., where A(i,j) is the number of ways in which we can add 2 distinct integers from the range 1..i in such a way that the sum is divisible by j.

n	a(n)
1	0
2	0
3	1
4	0
5	0
6	3
7	0
8	1
9	1
10	6
11	0
12	0
13	1
14	2
15	10
16	0
17	0
18	1
19	2
20	4
21	15
22	0
23	0
24	1
25	1
26	4
27	6
28	21
29	0
30	0
31	0
32	2
33	2
34	5
35	9
36	28
37	0
38	0
39	0
40	1
41	2
42	3
43	7
44	12
45	36
46	0
47	0
48	0
49	1
50	2
51	3
52	5
53	10
54	16
55	45
56	0
57	0
58	0
59	0
60	2
61	2
62	4
63	6
64	12
65	20
66	55
67	0
68	0
69	0
70	0
71	1
72	3
73	3
74	6
75	8
76	15
77	25
78	66
79	0
80	0
81	0
82	0

[0, 0, 1, 0, 0, 3, 0, 1, 1, 6, 0, 0, 1, 2, 10, 0, 0, 1, 2, 4, 15, 0, 0, 1, 1, 4, 6, 21, 0, 0, 0, 2, 2, 5, 9, 28, 0, 0, 0, 1, 2, 3, 7, 12, 36, 0, 0, 0, 1, 2, 3, 5, 10, 16, 45, 0, 0, 0, 0, 2, 2, 4, 6, 12, 20, 55, 0, 0, 0, 0, 1, 3, 3, 6, 8, 15, 25, 66, 0, 0, 0, 0]

cp's OEIS Frontend

A220691 Table A(i,j) read by antidiagonals in order A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), ..., where A(i,j) is the number of ways in which we can add 2 distinct integers from the range 1..i in such a way that the sum is divisible by j.

Table of values

List of values

n	a(n)
1	0
2	0
3	1
4	0
5	0
6	3
7	0
8	1
9	1
10	6
11	0
12	0
13	1
14	2
15	10
16	0
17	0
18	1
19	2
20	4
21	15
22	0
23	0
24	1
25	1
26	4
27	6
28	21
29	0
30	0
31	0
32	2
33	2
34	5
35	9
36	28
37	0
38	0
39	0
40	1
41	2
42	3
43	7
44	12
45	36
46	0
47	0
48	0
49	1
50	2
51	3
52	5
53	10
54	16
55	45
56	0
57	0
58	0
59	0
60	2
61	2
62	4
63	6
64	12
65	20
66	55
67	0
68	0
69	0
70	0
71	1
72	3
73	3
74	6
75	8
76	15
77	25
78	66
79	0
80	0
81	0
82	0

n	a(n)
1	0
2	0
3	1
4	0
5	0
6	3
7	0
8	1
9	1
10	6
11	0
12	0
13	1
14	2
15	10
16	0
17	0
18	1
19	2
20	4
21	15
22	0
23	0
24	1
25	1
26	4
27	6
28	21
29	0
30	0
31	0
32	2
33	2
34	5
35	9
36	28
37	0
38	0
39	0
40	1
41	2
42	3
43	7
44	12
45	36
46	0
47	0
48	0
49	1
50	2
51	3
52	5
53	10
54	16
55	45
56	0
57	0
58	0
59	0
60	2
61	2
62	4
63	6
64	12
65	20
66	55
67	0
68	0
69	0
70	0
71	1
72	3
73	3
74	6
75	8
76	15
77	25
78	66
79	0
80	0
81	0
82	0

n	a(n)
1	0
2	0
3	1
4	0
5	0
6	3
7	0
8	1
9	1
10	6
11	0
12	0
13	1
14	2
15	10
16	0
17	0
18	1
19	2
20	4
21	15
22	0
23	0
24	1
25	1
26	4
27	6
28	21
29	0
30	0
31	0
32	2
33	2
34	5
35	9
36	28
37	0
38	0
39	0
40	1
41	2
42	3
43	7
44	12
45	36
46	0
47	0
48	0
49	1
50	2
51	3
52	5
53	10
54	16
55	45
56	0
57	0
58	0
59	0
60	2
61	2
62	4
63	6
64	12
65	20
66	55
67	0
68	0
69	0
70	0
71	1
72	3
73	3
74	6
75	8
76	15
77	25
78	66
79	0
80	0
81	0
82	0