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.

A177542 Number of permutations of {1,...,n} avoiding adjacent step pattern up, down, up, down, down, down.

Table of values

n a(n)
0 1
1 1
2 2
3 6
4 24
5 120
6 720
7 4976
8 39296
9 349056
10 3444480
11 37382400
12 442506240
13 5674931536
14 78376004800
15 1159755383520
16 18305304913920
17 306984257241600
18 5451042337781760
19 102170107109747648
20 2015786374006453760
21 41759419845040968960
22 906291283573022730240

List of values

[1, 1, 2, 6, 24, 120, 720, 4976, 39296, 349056, 3444480, 37382400, 442506240, 5674931536, 78376004800, 1159755383520, 18305304913920, 306984257241600, 5451042337781760, 102170107109747648, 2015786374006453760, 41759419845040968960, 906291283573022730240]

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

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