A220183 - cp's OEIS frontend

A220183 Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k triple descents (n>=0,0<=k<=n-3). We say that i is a triple descent of a permutation p if p(i) > p(i+1) > p(i+2) > p(i+3).

n	a(n)
0	1
1	1
2	2
3	6
4	23
5	1
6	111
7	8
8	1
9	642
10	67
11	10
12	1
13	4326
14	602
15	99
16	12
17	1
18	33333
19	5742
20	1093
21	137
22	14
23	1
24	288901
25	59504
26	12425
27	1852
28	181
29	16
30	1
31	2782082
32	666834
33	151635
34	24970
35	3029
36	231
37	18
38	1
39	29471046
40	8054684
41	1981499
42	355906
43	48455
44	4902
45	287
46	20
47	1

[1, 1, 2, 6, 23, 1, 111, 8, 1, 642, 67, 10, 1, 4326, 602, 99, 12, 1, 33333, 5742, 1093, 137, 14, 1, 288901, 59504, 12425, 1852, 181, 16, 1, 2782082, 666834, 151635, 24970, 3029, 231, 18, 1, 29471046, 8054684, 1981499, 355906, 48455, 4902, 287, 20, 1]

cp's OEIS Frontend

A220183 Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k triple descents (n>=0,0<=k<=n-3). We say that i is a triple descent of a permutation p if p(i) > p(i+1) > p(i+2) > p(i+3).

Table of values

List of values