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.

A326412 Number of inversion sequences of length n where all consecutive subsequences i,j,k satisfy i >= j <= k or i <= j >= k.

Table of values

n a(n)
0 1
1 1
2 2
3 5
4 17
5 69
6 330
7 1797
8 11028
9 74932
10 559351
11 4540088
12 39840318
13 375421225
14 3782383945
15 40548234374
16 460956742449
17 5536790753853
18 70077462043662
19 931945968071778
20 12993337101354500
21 189485727877247991
22 2884989393948284323
23 45772604755492432599

List of values

[1, 1, 2, 5, 17, 69, 330, 1797, 11028, 74932, 559351, 4540088, 39840318, 375421225, 3782383945, 40548234374, 460956742449, 5536790753853, 70077462043662, 931945968071778, 12993337101354500, 189485727877247991, 2884989393948284323, 45772604755492432599]

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

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