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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A367313 Triangle read by rows: T(n,k) is the number of permutations of [n] with weighted inversion index k.

Table of values

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

List of values

[1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 3, 3, 4, 3, 3, 2, 1, 1, 1, 1, 2, 3, 5, 5, 8, 9, 10, 10, 12, 10, 10, 9, 8, 5, 5, 3, 2, 1, 1, 1, 1, 2, 3, 5, 7, 9, 12, 16, 20, 23, 28, 31, 36, 38, 41, 43, 44, 44, 43, 41, 38, 36, 31, 28, 23, 20, 16, 12, 9, 7, 5, 3, 2, 1, 1]

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