A123550 - cp's OEIS frontend

A123550 Triangle read by rows: T(n,k) = number of unlabeled connected bicolored graphs having 2n nodes and k edges, which are invariant when the two color classes are interchanged. Here n >= 0, 0 <= k <= n^2.

n	a(n)
1	0
2	1
3	0
4	0
5	0
6	1
7	1
8	0
9	0
10	0
11	0
12	0
13	2
14	2
15	1
16	1
17	1
18	0
19	0
20	0
21	0
22	0
23	0
24	0
25	4
26	6
27	6
28	6
29	5
30	4
31	2
32	1
33	1
34	1
35	0
36	0
37	0
38	0
39	0
40	0
41	0
42	0
43	0
44	9
45	15
46	23
47	31
48	36
49	34
50	31
51	27
52	21
53	14
54	9
55	6
56	4
57	2
58	1
59	1
60	1
61	0
62	0
63	0
64	0
65	0
66	0
67	0
68	0
69	0
70	0
71	0
72	20
73	44
74	84
75	134
76	196
77	249
78	288
79	313
80	317
81	303
82	267
83	224
84	180

[0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 2, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 4, 6, 6, 6, 5, 4, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 15, 23, 31, 36, 34, 31, 27, 21, 14, 9, 6, 4, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 20, 44, 84, 134, 196, 249, 288, 313, 317, 303, 267, 224, 180]

cp's OEIS Frontend

A123550 Triangle read by rows: T(n,k) = number of unlabeled connected bicolored graphs having 2n nodes and k edges, which are invariant when the two color classes are interchanged. Here n >= 0, 0 <= k <= n^2.

Table of values

List of values

n	a(n)
1	0
2	1
3	0
4	0
5	0
6	1
7	1
8	0
9	0
10	0
11	0
12	0
13	2
14	2
15	1
16	1
17	1
18	0
19	0
20	0
21	0
22	0
23	0
24	0
25	4
26	6
27	6
28	6
29	5
30	4
31	2
32	1
33	1
34	1
35	0
36	0
37	0
38	0
39	0
40	0
41	0
42	0
43	0
44	9
45	15
46	23
47	31
48	36
49	34
50	31
51	27
52	21
53	14
54	9
55	6
56	4
57	2
58	1
59	1
60	1
61	0
62	0
63	0
64	0
65	0
66	0
67	0
68	0
69	0
70	0
71	0
72	20
73	44
74	84
75	134
76	196
77	249
78	288
79	313
80	317
81	303
82	267
83	224
84	180

n	a(n)
1	0
2	1
3	0
4	0
5	0
6	1
7	1
8	0
9	0
10	0
11	0
12	0
13	2
14	2
15	1
16	1
17	1
18	0
19	0
20	0
21	0
22	0
23	0
24	0
25	4
26	6
27	6
28	6
29	5
30	4
31	2
32	1
33	1
34	1
35	0
36	0
37	0
38	0
39	0
40	0
41	0
42	0
43	0
44	9
45	15
46	23
47	31
48	36
49	34
50	31
51	27
52	21
53	14
54	9
55	6
56	4
57	2
58	1
59	1
60	1
61	0
62	0
63	0
64	0
65	0
66	0
67	0
68	0
69	0
70	0
71	0
72	20
73	44
74	84
75	134
76	196
77	249
78	288
79	313
80	317
81	303
82	267
83	224
84	180

n	a(n)
1	0
2	1
3	0
4	0
5	0
6	1
7	1
8	0
9	0
10	0
11	0
12	0
13	2
14	2
15	1
16	1
17	1
18	0
19	0
20	0
21	0
22	0
23	0
24	0
25	4
26	6
27	6
28	6
29	5
30	4
31	2
32	1
33	1
34	1
35	0
36	0
37	0
38	0
39	0
40	0
41	0
42	0
43	0
44	9
45	15
46	23
47	31
48	36
49	34
50	31
51	27
52	21
53	14
54	9
55	6
56	4
57	2
58	1
59	1
60	1
61	0
62	0
63	0
64	0
65	0
66	0
67	0
68	0
69	0
70	0
71	0
72	20
73	44
74	84
75	134
76	196
77	249
78	288
79	313
80	317
81	303
82	267
83	224
84	180