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.

A258830 Number of permutations p of [n] such that the up-down signature of 0,p has nonnegative partial sums.

Table of values

n a(n)
0 1
1 1
2 2
3 5
4 20
5 87
6 522
7 3271
8 26168
9 214955
10 2149550
11 21881103
12 262573236
13 3191361201
14 44679056814
15 631546127049
16 10104738032784
17 162891774138339
18 2932051934490102
19 53094870211027831
20 1061897404220556620
21 21342730463672017301
22 469540070200784380622

List of values

[1, 1, 2, 5, 20, 87, 522, 3271, 26168, 214955, 2149550, 21881103, 262573236, 3191361201, 44679056814, 631546127049, 10104738032784, 162891774138339, 2932051934490102, 53094870211027831, 1061897404220556620, 21342730463672017301, 469540070200784380622]

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

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