cp's OEIS Frontend

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.

A005287 Number of permutations of [n] with four inversions.

Table of values

n a(n)
4 5
5 20
6 49
7 98
8 174
9 285
10 440
11 649
12 923
13 1274
14 1715
15 2260
16 2924
17 3723
18 4674
19 5795
20 7105
21 8624
22 10373
23 12374
24 14650
25 17225
26 20124
27 23373
28 26999
29 31030
30 35495
31 40424
32 45848
33 51799
34 58310
35 65415
36 73149
37 81548
38 90649
39 100490
40 111110
41 122549
42 134848
43 148049

List of values

[5, 20, 49, 98, 174, 285, 440, 649, 923, 1274, 1715, 2260, 2924, 3723, 4674, 5795, 7105, 8624, 10373, 12374, 14650, 17225, 20124, 23373, 26999, 31030, 35495, 40424, 45848, 51799, 58310, 65415, 73149, 81548, 90649, 100490, 111110, 122549, 134848, 148049]