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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.

A186526 Number T(n,k) of permutations on n elements with exactly k 3-cycles; triangle read by rows.

Table of values

n a(n)
0 1
1 1
2 2
3 4
4 2
5 16
6 8
7 80
8 40
9 520
10 160
11 40
12 3640
13 1120
14 280
15 29120
16 8960
17 2240
18 259840
19 87360
20 13440
21 2240
22 2598400
23 873600
24 134400
25 22400
26 28582400
27 9609600
28 1478400
29 246400
30 343235200
31 114329600
32 19219200
33 1971200
34 246400
35 4462057600
36 1486284800
37 249849600
38 25625600
39 3203200
40 62468806400
41 20807987200
42 3497894400
43 358758400
44 44844800
45 936987251200
46 312344032000
47 52019968000
48 5829824000
49 448448000
50 44844800

List of values

[1, 1, 2, 4, 2, 16, 8, 80, 40, 520, 160, 40, 3640, 1120, 280, 29120, 8960, 2240, 259840, 87360, 13440, 2240, 2598400, 873600, 134400, 22400, 28582400, 9609600, 1478400, 246400, 343235200, 114329600, 19219200, 1971200, 246400, 4462057600, 1486284800, 249849600, 25625600, 3203200, 62468806400, 20807987200, 3497894400, 358758400, 44844800, 936987251200, 312344032000, 52019968000, 5829824000, 448448000, 44844800]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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