A067310 - cp's OEIS frontend

A067310 Square table read by antidiagonals of number of ways of arranging n chords on a circle with k simple intersections (i.e., no intersections with 3 or more chords).

n	a(n)
0	1
1	0
2	1
3	0
4	0
5	2
6	0
7	0
8	1
9	5
10	0
11	0
12	0
13	6
14	14
15	0
16	0
17	0
18	3
19	28
20	42
21	0
22	0
23	0
24	1
25	28
26	120
27	132
28	0
29	0
30	0
31	0
32	20
33	180
34	495
35	429
36	0
37	0
38	0
39	0
40	10
41	195
42	990
43	2002
44	1430
45	0
46	0
47	0
48	0
49	4
50	165
51	1430
52	5005
53	8008
54	4862
55	0
56	0
57	0
58	0
59	1
60	117
61	1650
62	9009
63	24024
64	31824
65	16796
66	0
67	0
68	0
69	0
70	0
71	70
72	1617

[1, 0, 1, 0, 0, 2, 0, 0, 1, 5, 0, 0, 0, 6, 14, 0, 0, 0, 3, 28, 42, 0, 0, 0, 1, 28, 120, 132, 0, 0, 0, 0, 20, 180, 495, 429, 0, 0, 0, 0, 10, 195, 990, 2002, 1430, 0, 0, 0, 0, 4, 165, 1430, 5005, 8008, 4862, 0, 0, 0, 0, 1, 117, 1650, 9009, 24024, 31824, 16796, 0, 0, 0, 0, 0, 70, 1617]

cp's OEIS Frontend

A067310 Square table read by antidiagonals of number of ways of arranging n chords on a circle with k simple intersections (i.e., no intersections with 3 or more chords).

Table of values

List of values