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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.

A186766 Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k nonincreasing odd cycles (0<=k<=floor(n/3)). 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 odd if it has an odd number of entries. For example, the permutation (152)(347)(6)(8) has 1 nonincreasing odd cycle.

Table of values

n a(n)
0 1
1 1
2 2
3 5
4 1
5 20
6 4
7 77
8 43
9 472
10 238
11 10
12 2585
13 2385
14 70
15 21968
16 16504
17 1848
18 157113
19 189695
20 15792
21 280
22 1724064
23 1591082
24 310854
25 2800
26 15229645
27 21449481
28 3100614
29 137060
30 204738624
31 213397204
32 59267252
33 1583120
34 15400
35 2151199429
36 3347368503
37 676271024
38 51981644
39 200200

List of values

[1, 1, 2, 5, 1, 20, 4, 77, 43, 472, 238, 10, 2585, 2385, 70, 21968, 16504, 1848, 157113, 189695, 15792, 280, 1724064, 1591082, 310854, 2800, 15229645, 21449481, 3100614, 137060, 204738624, 213397204, 59267252, 1583120, 15400, 2151199429, 3347368503, 676271024, 51981644, 200200]