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.

A262164 Number of permutations p of [n] such that the up-down signature of 0,p has nonnegative partial sums with a maximal value <= 2.

Table of values

n a(n)
0 1
1 1
2 2
3 4
4 16
5 54
6 324
7 1532
8 12256
9 74512
10 745120
11 5536752
12 66441024
13 583466480
14 8168530720
15 82769713504
16 1324315416064
17 15208157533440
18 273746835601920
19 3513491887566848
20 70269837751336960
21 996837786288583168
22 21930431298348829696
23 340730692136161864704

List of values

[1, 1, 2, 4, 16, 54, 324, 1532, 12256, 74512, 745120, 5536752, 66441024, 583466480, 8168530720, 82769713504, 1324315416064, 15208157533440, 273746835601920, 3513491887566848, 70269837751336960, 996837786288583168, 21930431298348829696, 340730692136161864704]

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

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