A180186 - cp's OEIS frontend

A180186 Triangle read by rows: T(n,k) is the number of permutations of [n] starting with 1, having no 3-sequences and having k successions (0 <= k <= floor(n/2)); a succession of a permutation p is a position i such that p(i +1) - p(i) = 1.

n	a(n)
0	1
1	1
2	0
3	1
4	1
5	0
6	2
7	3
8	0
9	9
10	8
11	3
12	44
13	45
14	12
15	1
16	265
17	264
18	90
19	8
20	1854
21	1855
22	660
23	90
24	2
25	14833
26	14832
27	5565
28	880
29	45
30	133496
31	133497
32	51912
33	9275
34	660
35	9
36	1334961
37	1334960
38	533988
39	103824
40	9275
41	264
42	14684570
43	14684571
44	6007320
45	1245972
46	129780
47	5565

[1, 1, 0, 1, 1, 0, 2, 3, 0, 9, 8, 3, 44, 45, 12, 1, 265, 264, 90, 8, 1854, 1855, 660, 90, 2, 14833, 14832, 5565, 880, 45, 133496, 133497, 51912, 9275, 660, 9, 1334961, 1334960, 533988, 103824, 9275, 264, 14684570, 14684571, 6007320, 1245972, 129780, 5565]

cp's OEIS Frontend

A180186 Triangle read by rows: T(n,k) is the number of permutations of [n] starting with 1, having no 3-sequences and having k successions (0 <= k <= floor(n/2)); a succession of a permutation p is a position i such that p(i +1) - p(i) = 1.

Table of values

List of values