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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.

A371698 Number of partial order-preserving or -reversing transformations of a chain of length n.

Table of values

n a(n)
1 2
2 9
3 54
4 323
5 1848
6 10293
7 56738
8 312327
9 1723692
10 9549785
11 53121654
12 296593547
13 1661423104
14 9333552509
15 52565738570
16 296696569871
17 1677887732820
18 9505147063713
19 53928737011358
20 306393222740883
21 1742919983985192
22 9925790283119429
23 56584658970159474
24 322879453747840023

List of values

[2, 9, 54, 323, 1848, 10293, 56738, 312327, 1723692, 9549785, 53121654, 296593547, 1661423104, 9333552509, 52565738570, 296696569871, 1677887732820, 9505147063713, 53928737011358, 306393222740883, 1742919983985192, 9925790283119429, 56584658970159474, 322879453747840023]

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

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