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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.

A227937 Partitions of n labeled elements into subsets of two or three elements.

Table of values

n a(n)
0 1
1 0
2 1
3 1
4 3
5 10
6 25
7 105
8 385
9 1540
10 7245
11 32725
12 164395
13 870870
14 4689685
15 27152125
16 161786625
17 997196200
18 6443061625
19 42702885225
20 292938721075
21 2078239413250
22 15119319039825
23 113390111659825
24 873538909468225
25 6894294734827500
26 55855506234653125
27 463151808682688125
28 3927996120260086875
29 34081631999814148750
30 301951521812713898125
31 2731127272307562253125
32 25208456056107710010625
33 237164027532948085570000

List of values

[1, 0, 1, 1, 3, 10, 25, 105, 385, 1540, 7245, 32725, 164395, 870870, 4689685, 27152125, 161786625, 997196200, 6443061625, 42702885225, 292938721075, 2078239413250, 15119319039825, 113390111659825, 873538909468225, 6894294734827500, 55855506234653125, 463151808682688125, 3927996120260086875, 34081631999814148750, 301951521812713898125, 2731127272307562253125, 25208456056107710010625, 237164027532948085570000]

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

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