cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A086853 Number of permutations of length n with exactly 2 rising or falling successions.

Table of values

n a(n)
0 0
1 0
2 0
3 2
4 10
5 48
6 256
7 1670
8 12846
9 112820
10 1108612
11 12032154
12 142852450
13 1840969784
14 25587270600
15 381460235918
16 6071318154166
17 102742200205980
18 1841978156709676
19 34874169034136930
20 695294184953602602
21 14560120360421802464
22 319510983674891800240

List of values

[0, 0, 0, 2, 10, 48, 256, 1670, 12846, 112820, 1108612, 12032154, 142852450, 1840969784, 25587270600, 381460235918, 6071318154166, 102742200205980, 1841978156709676, 34874169034136930, 695294184953602602, 14560120360421802464, 319510983674891800240]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.