A384186 - cp's OEIS frontend

A384186 Number of permutations of 1, 2,..., n with exactly one rising or falling successon, namely (n-1)n or n(n-1).

n	a(n)
1	0
2	2
3	2
4	2
5	6
6	34
7	214
8	1506
9	11990
10	107234
11	1065846
12	11659426
13	139217494
14	1801784610
15	25124797046
16	375531165794
17	5989287277014
18	101524201538146
19	1822662037112950
20	34548339122512674
21	689469487015534166
22	14450128299126915746

[0, 2, 2, 2, 6, 34, 214, 1506, 11990, 107234, 1065846, 11659426, 139217494, 1801784610, 25124797046, 375531165794, 5989287277014, 101524201538146, 1822662037112950, 34548339122512674, 689469487015534166, 14450128299126915746]

cp's OEIS Frontend

A384186 Number of permutations of 1, 2,..., n with exactly one rising or falling successon, namely (n-1)n or n(n-1).

Table of values

List of values