A238416 - cp's OEIS frontend

A238416 Triangle read by rows: T(n,k) is the number of trees with n vertices having k vertices of degree 2 (n>=2, 0 <= k <= n - 2).

n	a(n)
2	1
3	0
4	1
5	1
6	0
7	1
8	1
9	1
10	0
11	1
12	2
13	1
14	2
15	0
16	1
17	2
18	3
19	2
20	3
21	0
22	1
23	4
24	4
25	7
26	3
27	4
28	0
29	1
30	5
31	9
32	10
33	12
34	5
35	5
36	0
37	1
38	10
39	15
40	25
41	20
42	22
43	6
44	7
45	0
46	1
47	14
48	31
49	46
50	54
51	38
52	34
53	9
54	8
55	0
56	1
57	26
58	57
59	103
60	111
61	114
62	65
63	53
64	11
65	10
66	0
67	1
68	42
69	114
70	204
71	267
72	250
73	212
74	108
75	76
76	15
77	12
78	0
79	1
80	78
81	219
82	440
83	583
84	644
85	502
86	383
87	167
88	110
89	18
90	14
91	0
92	1

[1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 2, 1, 2, 0, 1, 2, 3, 2, 3, 0, 1, 4, 4, 7, 3, 4, 0, 1, 5, 9, 10, 12, 5, 5, 0, 1, 10, 15, 25, 20, 22, 6, 7, 0, 1, 14, 31, 46, 54, 38, 34, 9, 8, 0, 1, 26, 57, 103, 111, 114, 65, 53, 11, 10, 0, 1, 42, 114, 204, 267, 250, 212, 108, 76, 15, 12, 0, 1, 78, 219, 440, 583, 644, 502, 383, 167, 110, 18, 14, 0, 1]

cp's OEIS Frontend

A238416 Triangle read by rows: T(n,k) is the number of trees with n vertices having k vertices of degree 2 (n>=2, 0 <= k <= n - 2).

Table of values

List of values

n	a(n)
2	1
3	0
4	1
5	1
6	0
7	1
8	1
9	1
10	0
11	1
12	2
13	1
14	2
15	0
16	1
17	2
18	3
19	2
20	3
21	0
22	1
23	4
24	4
25	7
26	3
27	4
28	0
29	1
30	5
31	9
32	10
33	12
34	5
35	5
36	0
37	1
38	10
39	15
40	25
41	20
42	22
43	6
44	7
45	0
46	1
47	14
48	31
49	46
50	54
51	38
52	34
53	9
54	8
55	0
56	1
57	26
58	57
59	103
60	111
61	114
62	65
63	53
64	11
65	10
66	0
67	1
68	42
69	114
70	204
71	267
72	250
73	212
74	108
75	76
76	15
77	12
78	0
79	1
80	78
81	219
82	440
83	583
84	644
85	502
86	383
87	167
88	110
89	18
90	14
91	0
92	1

n	a(n)
2	1
3	0
4	1
5	1
6	0
7	1
8	1
9	1
10	0
11	1
12	2
13	1
14	2
15	0
16	1
17	2
18	3
19	2
20	3
21	0
22	1
23	4
24	4
25	7
26	3
27	4
28	0
29	1
30	5
31	9
32	10
33	12
34	5
35	5
36	0
37	1
38	10
39	15
40	25
41	20
42	22
43	6
44	7
45	0
46	1
47	14
48	31
49	46
50	54
51	38
52	34
53	9
54	8
55	0
56	1
57	26
58	57
59	103
60	111
61	114
62	65
63	53
64	11
65	10
66	0
67	1
68	42
69	114
70	204
71	267
72	250
73	212
74	108
75	76
76	15
77	12
78	0
79	1
80	78
81	219
82	440
83	583
84	644
85	502
86	383
87	167
88	110
89	18
90	14
91	0
92	1

n	a(n)
2	1
3	0
4	1
5	1
6	0
7	1
8	1
9	1
10	0
11	1
12	2
13	1
14	2
15	0
16	1
17	2
18	3
19	2
20	3
21	0
22	1
23	4
24	4
25	7
26	3
27	4
28	0
29	1
30	5
31	9
32	10
33	12
34	5
35	5
36	0
37	1
38	10
39	15
40	25
41	20
42	22
43	6
44	7
45	0
46	1
47	14
48	31
49	46
50	54
51	38
52	34
53	9
54	8
55	0
56	1
57	26
58	57
59	103
60	111
61	114
62	65
63	53
64	11
65	10
66	0
67	1
68	42
69	114
70	204
71	267
72	250
73	212
74	108
75	76
76	15
77	12
78	0
79	1
80	78
81	219
82	440
83	583
84	644
85	502
86	383
87	167
88	110
89	18
90	14
91	0
92	1