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.

A320976 Number of permutations p of [n] such that the up-down signature of p has nonnegative partial sums with a maximal value of two.

Table of values

n a(n)
2 0
3 1
4 3
5 24
6 101
7 862
8 4743
9 47216
10 322039
11 3744368
12 30517747
13 409498400
14 3884904379
15 59360223088
16 642766195887
17 11046815693568
18 134468538125519
19 2571506053105408
20 34764547687430955
21 732881798335913984
22 10895866774781276947
23 251184536044504689152

List of values

[0, 1, 3, 24, 101, 862, 4743, 47216, 322039, 3744368, 30517747, 409498400, 3884904379, 59360223088, 642766195887, 11046815693568, 134468538125519, 2571506053105408, 34764547687430955, 732881798335913984, 10895866774781276947, 251184536044504689152]

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

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