A380993 - cp's OEIS frontend

A380993 Irregular triangular array read by rows. T(n,k) is the number of ternary words of length n containing at least one copy of each letter and having exactly k inversions, n>=3, 0<=k<=floor(n^2/3).

n	a(n)
3	1
4	2
5	2
6	1
7	3
8	6
9	9
10	9
11	6
12	3
13	6
14	12
15	21
16	27
17	30
18	24
19	18
20	9
21	3
22	10
23	20
24	38
25	55
26	74
27	81
28	80
29	69
30	53
31	34
32	17
33	8
34	1
35	15
36	30
37	60
38	93
39	138
40	174
41	210
42	216
43	219
44	195
45	165
46	120
47	84
48	48
49	27
50	9
51	3
52	21
53	42
54	87
55	141
56	222
57	303
58	405
59	480
60	546
61	579
62	588
63	552
64	498
65	414
66	324
67	240
68	162
69	99
70	54
71	27
72	9
73	3

[1, 2, 2, 1, 3, 6, 9, 9, 6, 3, 6, 12, 21, 27, 30, 24, 18, 9, 3, 10, 20, 38, 55, 74, 81, 80, 69, 53, 34, 17, 8, 1, 15, 30, 60, 93, 138, 174, 210, 216, 219, 195, 165, 120, 84, 48, 27, 9, 3, 21, 42, 87, 141, 222, 303, 405, 480, 546, 579, 588, 552, 498, 414, 324, 240, 162, 99, 54, 27, 9, 3]

cp's OEIS Frontend

A380993 Irregular triangular array read by rows. T(n,k) is the number of ternary words of length n containing at least one copy of each letter and having exactly k inversions, n>=3, 0<=k<=floor(n^2/3).

Table of values

List of values

n	a(n)
3	1
4	2
5	2
6	1
7	3
8	6
9	9
10	9
11	6
12	3
13	6
14	12
15	21
16	27
17	30
18	24
19	18
20	9
21	3
22	10
23	20
24	38
25	55
26	74
27	81
28	80
29	69
30	53
31	34
32	17
33	8
34	1
35	15
36	30
37	60
38	93
39	138
40	174
41	210
42	216
43	219
44	195
45	165
46	120
47	84
48	48
49	27
50	9
51	3
52	21
53	42
54	87
55	141
56	222
57	303
58	405
59	480
60	546
61	579
62	588
63	552
64	498
65	414
66	324
67	240
68	162
69	99
70	54
71	27
72	9
73	3

n	a(n)
3	1
4	2
5	2
6	1
7	3
8	6
9	9
10	9
11	6
12	3
13	6
14	12
15	21
16	27
17	30
18	24
19	18
20	9
21	3
22	10
23	20
24	38
25	55
26	74
27	81
28	80
29	69
30	53
31	34
32	17
33	8
34	1
35	15
36	30
37	60
38	93
39	138
40	174
41	210
42	216
43	219
44	195
45	165
46	120
47	84
48	48
49	27
50	9
51	3
52	21
53	42
54	87
55	141
56	222
57	303
58	405
59	480
60	546
61	579
62	588
63	552
64	498
65	414
66	324
67	240
68	162
69	99
70	54
71	27
72	9
73	3

n	a(n)
3	1
4	2
5	2
6	1
7	3
8	6
9	9
10	9
11	6
12	3
13	6
14	12
15	21
16	27
17	30
18	24
19	18
20	9
21	3
22	10
23	20
24	38
25	55
26	74
27	81
28	80
29	69
30	53
31	34
32	17
33	8
34	1
35	15
36	30
37	60
38	93
39	138
40	174
41	210
42	216
43	219
44	195
45	165
46	120
47	84
48	48
49	27
50	9
51	3
52	21
53	42
54	87
55	141
56	222
57	303
58	405
59	480
60	546
61	579
62	588
63	552
64	498
65	414
66	324
67	240
68	162
69	99
70	54
71	27
72	9
73	3