A187244 - cp's OEIS frontend

A187244 Triangle read by rows: T(n,k) is the number of permutations of [n] having k cycles with 2 alternating runs (it is assumed that the smallest element of the cycle is in the first position), 0<=k<=floor(n/3).

n	a(n)
0	1
1	1
2	2
3	5
4	1
5	17
6	7
7	78
8	42
9	463
10	247
11	10
12	3315
13	1550
14	175
15	27164
16	11049
17	2107
18	247975
19	92596
20	22029
21	280
22	2492539
23	906427
24	220734
25	9100
26	27422698
27	10044963
28	2264724
29	184415
30	328607417
31	122314296
32	25036462
33	3028025
34	15400
35	4266367567
36	1607778568
37	307273681
38	44800184
39	800800

[1, 1, 2, 5, 1, 17, 7, 78, 42, 463, 247, 10, 3315, 1550, 175, 27164, 11049, 2107, 247975, 92596, 22029, 280, 2492539, 906427, 220734, 9100, 27422698, 10044963, 2264724, 184415, 328607417, 122314296, 25036462, 3028025, 15400, 4266367567, 1607778568, 307273681, 44800184, 800800]

cp's OEIS Frontend

A187244 Triangle read by rows: T(n,k) is the number of permutations of [n] having k cycles with 2 alternating runs (it is assumed that the smallest element of the cycle is in the first position), 0<=k<=floor(n/3).

Table of values

List of values