A010030 - cp's OEIS frontend

A010030 Irregular triangle read by rows: T(n,k) (n >= 1, 0 <= k <= [n/2]) = number of permutations of 1..n with [n/2]-k runs of consecutive pairs up and down (divided by 2).

n	a(n)
1	1
2	1
3	0
4	3
5	0
6	3
7	8
8	1
9	25
10	28
11	7
12	17
13	155
14	143
15	45
16	259
17	1005
18	933
19	323
20	131
21	2770
22	7488
23	7150
24	2621
25	3177
26	27978
27	64164
28	62310
29	23811
30	1281
31	51433
32	294602
33	619986
34	607445
35	239653

[1, 1, 0, 3, 0, 3, 8, 1, 25, 28, 7, 17, 155, 143, 45, 259, 1005, 933, 323, 131, 2770, 7488, 7150, 2621, 3177, 27978, 64164, 62310, 23811, 1281, 51433, 294602, 619986, 607445, 239653]

cp's OEIS Frontend

A010030 Irregular triangle read by rows: T(n,k) (n >= 1, 0 <= k <= [n/2]) = number of permutations of 1..n with [n/2]-k runs of consecutive pairs up and down (divided by 2).

Table of values

List of values