A180573 - cp's OEIS frontend

A180573 Triangle read by rows: T(n,k) is the number of unordered pairs of vertices at distance k in the sun graph on 2n nodes. The sun graph on 2n nodes is obtained by attaching n pendant edges to the cycle graph on n nodes.

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

[6, 6, 3, 8, 10, 8, 2, 10, 15, 15, 5, 12, 18, 21, 12, 3, 14, 21, 28, 21, 7, 16, 24, 32, 28, 16, 4, 18, 27, 36, 36, 27, 9, 20, 30, 40, 40, 35, 20, 5, 22, 33, 44, 44, 44, 33, 11, 24, 36, 48, 48, 48, 42, 24, 6, 26, 39, 52, 52, 52, 52, 39, 13, 28, 42, 56, 56, 56, 56, 49, 28, 7, 30, 45, 60]

cp's OEIS Frontend

A180573 Triangle read by rows: T(n,k) is the number of unordered pairs of vertices at distance k in the sun graph on 2n nodes. The sun graph on 2n nodes is obtained by attaching n pendant edges to the cycle graph on n nodes.

Table of values

List of values

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

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

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