A010028 - cp's OEIS frontend

A010028 Triangle read by rows: T(n,k) is one-half the number of permutations of length n with exactly n-k rising or falling successions, for n >= 1, 1 <= k <= n. T(1,1) = 1 by convention.

n	a(n)
1	1
2	1
3	0
4	1
5	2
6	0
7	1
8	5
9	5
10	1
11	1
12	8
13	24
14	20
15	7
16	1
17	11
18	60
19	128
20	115
21	45
22	1
23	14
24	113
25	444
26	835
27	790
28	323
29	1
30	17
31	183
32	1099
33	3599
34	6423
35	6217
36	2621
37	1
38	20
39	270
40	2224
41	11060
42	32484
43	56410
44	55160
45	23811
46	1
47	23
48	374
49	3950
50	27152
51	118484
52	325322
53	554306
54	545135
55	239653

[1, 1, 0, 1, 2, 0, 1, 5, 5, 1, 1, 8, 24, 20, 7, 1, 11, 60, 128, 115, 45, 1, 14, 113, 444, 835, 790, 323, 1, 17, 183, 1099, 3599, 6423, 6217, 2621, 1, 20, 270, 2224, 11060, 32484, 56410, 55160, 23811, 1, 23, 374, 3950, 27152, 118484, 325322, 554306, 545135, 239653]

cp's OEIS Frontend

A010028 Triangle read by rows: T(n,k) is one-half the number of permutations of length n with exactly n-k rising or falling successions, for n >= 1, 1 <= k <= n. T(1,1) = 1 by convention.

Table of values

List of values