A279681 - cp's OEIS frontend

A279681 Irregular triangle read by rows: possible numbers of diagonals of convex polyhedra having n vertices.

n	a(n)
4	0
5	0
6	1
7	0
8	1
9	2
10	3
11	0
12	1
13	2
14	3
15	4
16	5
17	6
18	0
19	2
20	3
21	4
22	5
23	6
24	7
25	8
26	9
27	10
28	0
29	3
30	4
31	5
32	6
33	7
34	8
35	9
36	10
37	11
38	12
39	13
40	14
41	15
42	0
43	4
44	5
45	6
46	7
47	8
48	9
49	10
50	11
51	12
52	13
53	14
54	15
55	16
56	17
57	18
58	19
59	20
60	21
61	0
62	5
63	6
64	7
65	8
66	9
67	10
68	11
69	12
70	13
71	14
72	15
73	16
74	17
75	18
76	19
77	20
78	21
79	22
80	23
81	24
82	25
83	26
84	27
85	28

[0, 0, 1, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 6, 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 0, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28]

cp's OEIS Frontend

A279681 Irregular triangle read by rows: possible numbers of diagonals of convex polyhedra having n vertices.

Table of values

List of values

n	a(n)
4	0
5	0
6	1
7	0
8	1
9	2
10	3
11	0
12	1
13	2
14	3
15	4
16	5
17	6
18	0
19	2
20	3
21	4
22	5
23	6
24	7
25	8
26	9
27	10
28	0
29	3
30	4
31	5
32	6
33	7
34	8
35	9
36	10
37	11
38	12
39	13
40	14
41	15
42	0
43	4
44	5
45	6
46	7
47	8
48	9
49	10
50	11
51	12
52	13
53	14
54	15
55	16
56	17
57	18
58	19
59	20
60	21
61	0
62	5
63	6
64	7
65	8
66	9
67	10
68	11
69	12
70	13
71	14
72	15
73	16
74	17
75	18
76	19
77	20
78	21
79	22
80	23
81	24
82	25
83	26
84	27
85	28

n	a(n)
4	0
5	0
6	1
7	0
8	1
9	2
10	3
11	0
12	1
13	2
14	3
15	4
16	5
17	6
18	0
19	2
20	3
21	4
22	5
23	6
24	7
25	8
26	9
27	10
28	0
29	3
30	4
31	5
32	6
33	7
34	8
35	9
36	10
37	11
38	12
39	13
40	14
41	15
42	0
43	4
44	5
45	6
46	7
47	8
48	9
49	10
50	11
51	12
52	13
53	14
54	15
55	16
56	17
57	18
58	19
59	20
60	21
61	0
62	5
63	6
64	7
65	8
66	9
67	10
68	11
69	12
70	13
71	14
72	15
73	16
74	17
75	18
76	19
77	20
78	21
79	22
80	23
81	24
82	25
83	26
84	27
85	28

n	a(n)
4	0
5	0
6	1
7	0
8	1
9	2
10	3
11	0
12	1
13	2
14	3
15	4
16	5
17	6
18	0
19	2
20	3
21	4
22	5
23	6
24	7
25	8
26	9
27	10
28	0
29	3
30	4
31	5
32	6
33	7
34	8
35	9
36	10
37	11
38	12
39	13
40	14
41	15
42	0
43	4
44	5
45	6
46	7
47	8
48	9
49	10
50	11
51	12
52	13
53	14
54	15
55	16
56	17
57	18
58	19
59	20
60	21
61	0
62	5
63	6
64	7
65	8
66	9
67	10
68	11
69	12
70	13
71	14
72	15
73	16
74	17
75	18
76	19
77	20
78	21
79	22
80	23
81	24
82	25
83	26
84	27
85	28