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.

A186764 Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k increasing even cycles (0<=k<=n). A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1) . A cycle is said to be even if it has an even number of entries. For example, the permutation (18)(2347)(569) has 2 increasing even cycles.

Table of values

n a(n)
0 1
1 1
2 1
3 1
4 3
5 3
6 14
7 7
8 3
9 70
10 35
11 15
12 419
13 226
14 60
15 15
16 2933
17 1582
18 420
19 105
20 23421
21 12741
22 3423
23 630
24 105
25 210789
26 114669
27 30807
28 5670
29 945
30 2108144
31 1144921
32 311160
33 55755
34 7875
35 945
36 23189584
37 12594131
38 3422760
39 613305
40 86625
41 10395
42 278279165
43 151125052
44 41041968
45 7429290
46 1001385
47 114345
48 10395

List of values

[1, 1, 1, 1, 3, 3, 14, 7, 3, 70, 35, 15, 419, 226, 60, 15, 2933, 1582, 420, 105, 23421, 12741, 3423, 630, 105, 210789, 114669, 30807, 5670, 945, 2108144, 1144921, 311160, 55755, 7875, 945, 23189584, 12594131, 3422760, 613305, 86625, 10395, 278279165, 151125052, 41041968, 7429290, 1001385, 114345, 10395]