A309937 - cp's OEIS frontend

A309937 Irregular triangle read by rows: T(n,k) is the number of compositions of n with 2k parts and circular differences all equal to 1 or -1, (n >= 3, 1 <= k <= n/3).

n	a(n)
3	2
4	0
5	2
6	0
7	2
8	2
9	0
10	0
11	4
12	2
13	0
14	2
15	0
16	2
17	0
18	2
19	0
20	6
21	0
22	4
23	0
24	2
25	2
26	0
27	6
28	0
29	0
30	2
31	0
32	8
33	2
34	0
35	8
36	0
37	2
38	0
39	4
40	0
41	12
42	0
43	2
44	0
45	6
46	0
47	10
48	0
49	2
50	0
51	16
52	0
53	2
54	2
55	0
56	6
57	0
58	20
59	0
60	0
61	4
62	0
63	18
64	0
65	12
66	2
67	0
68	8
69	0
70	30
71	0
72	2
73	0
74	2
75	0
76	16
77	0
78	30
79	0
80	2
81	0
82	6
83	0
84	40
85	0
86	14
87	0
88	4
89	0
90	20
91	0
92	52
93	0
94	2

[2, 0, 2, 0, 2, 2, 0, 0, 4, 2, 0, 2, 0, 2, 0, 2, 0, 6, 0, 4, 0, 2, 2, 0, 6, 0, 0, 2, 0, 8, 2, 0, 8, 0, 2, 0, 4, 0, 12, 0, 2, 0, 6, 0, 10, 0, 2, 0, 16, 0, 2, 2, 0, 6, 0, 20, 0, 0, 4, 0, 18, 0, 12, 2, 0, 8, 0, 30, 0, 2, 0, 2, 0, 16, 0, 30, 0, 2, 0, 6, 0, 40, 0, 14, 0, 4, 0, 20, 0, 52, 0, 2]

cp's OEIS Frontend

A309937 Irregular triangle read by rows: T(n,k) is the number of compositions of n with 2k parts and circular differences all equal to 1 or -1, (n >= 3, 1 <= k <= n/3).

Table of values

List of values

n	a(n)
3	2
4	0
5	2
6	0
7	2
8	2
9	0
10	0
11	4
12	2
13	0
14	2
15	0
16	2
17	0
18	2
19	0
20	6
21	0
22	4
23	0
24	2
25	2
26	0
27	6
28	0
29	0
30	2
31	0
32	8
33	2
34	0
35	8
36	0
37	2
38	0
39	4
40	0
41	12
42	0
43	2
44	0
45	6
46	0
47	10
48	0
49	2
50	0
51	16
52	0
53	2
54	2
55	0
56	6
57	0
58	20
59	0
60	0
61	4
62	0
63	18
64	0
65	12
66	2
67	0
68	8
69	0
70	30
71	0
72	2
73	0
74	2
75	0
76	16
77	0
78	30
79	0
80	2
81	0
82	6
83	0
84	40
85	0
86	14
87	0
88	4
89	0
90	20
91	0
92	52
93	0
94	2

n	a(n)
3	2
4	0
5	2
6	0
7	2
8	2
9	0
10	0
11	4
12	2
13	0
14	2
15	0
16	2
17	0
18	2
19	0
20	6
21	0
22	4
23	0
24	2
25	2
26	0
27	6
28	0
29	0
30	2
31	0
32	8
33	2
34	0
35	8
36	0
37	2
38	0
39	4
40	0
41	12
42	0
43	2
44	0
45	6
46	0
47	10
48	0
49	2
50	0
51	16
52	0
53	2
54	2
55	0
56	6
57	0
58	20
59	0
60	0
61	4
62	0
63	18
64	0
65	12
66	2
67	0
68	8
69	0
70	30
71	0
72	2
73	0
74	2
75	0
76	16
77	0
78	30
79	0
80	2
81	0
82	6
83	0
84	40
85	0
86	14
87	0
88	4
89	0
90	20
91	0
92	52
93	0
94	2

n	a(n)
3	2
4	0
5	2
6	0
7	2
8	2
9	0
10	0
11	4
12	2
13	0
14	2
15	0
16	2
17	0
18	2
19	0
20	6
21	0
22	4
23	0
24	2
25	2
26	0
27	6
28	0
29	0
30	2
31	0
32	8
33	2
34	0
35	8
36	0
37	2
38	0
39	4
40	0
41	12
42	0
43	2
44	0
45	6
46	0
47	10
48	0
49	2
50	0
51	16
52	0
53	2
54	2
55	0
56	6
57	0
58	20
59	0
60	0
61	4
62	0
63	18
64	0
65	12
66	2
67	0
68	8
69	0
70	30
71	0
72	2
73	0
74	2
75	0
76	16
77	0
78	30
79	0
80	2
81	0
82	6
83	0
84	40
85	0
86	14
87	0
88	4
89	0
90	20
91	0
92	52
93	0
94	2