A213910 - cp's OEIS frontend

A213910 Irregular triangle read by rows: T(n,k) is the number of involutions of length n that have exactly k inversions; n>=0, 0<=k<=binomial(n,2).

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

[1, 1, 1, 1, 1, 2, 0, 1, 1, 3, 1, 2, 1, 1, 1, 1, 4, 3, 3, 4, 2, 4, 1, 3, 0, 1, 1, 5, 6, 5, 9, 5, 10, 5, 9, 4, 7, 3, 3, 2, 1, 1, 1, 6, 10, 9, 16, 13, 19, 17, 19, 19, 17, 19, 13, 17, 7, 13, 3, 8, 1, 4, 0, 1, 1, 7, 15, 16, 26, 29, 34, 43, 39, 54, 41, 61, 40, 62, 36, 58, 28, 47, 21, 34, 15, 21, 10, 11, 6, 4, 3, 1, 1]

cp's OEIS Frontend

A213910 Irregular triangle read by rows: T(n,k) is the number of involutions of length n that have exactly k inversions; n>=0, 0<=k<=binomial(n,2).

Table of values

List of values

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

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

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