A180568 - cp's OEIS frontend

A180568 Triangle read by rows: T(n,k) is the number of unordered pairs of nodes at distance k in the grid P_3 x P_n (1<=k<=n), where P_j denotes the path graph on j nodes.

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

[2, 1, 7, 6, 2, 12, 14, 8, 2, 17, 22, 17, 8, 2, 22, 30, 26, 17, 8, 2, 27, 38, 35, 26, 17, 8, 2, 32, 46, 44, 35, 26, 17, 8, 2, 37, 54, 53, 44, 35, 26, 17, 8, 2, 42, 62, 62, 53, 44, 35, 26, 17, 8, 2, 47, 70, 71, 62, 53, 44, 35, 26, 17, 8, 2, 52, 78, 80, 71, 62, 53, 44, 35, 26, 17, 8, 2, 57]

cp's OEIS Frontend

A180568 Triangle read by rows: T(n,k) is the number of unordered pairs of nodes at distance k in the grid P_3 x P_n (1<=k<=n), where P_j denotes the path graph on j nodes.

Table of values

List of values

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

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

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