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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.

A354507 a(n) = n! * Sum_{k=1..n} ( Sum_{d|k} (-1)^(k/d+1) * d )/(k * (n-k)!).

Table of values

n a(n)
1 1
2 3
3 14
4 48
5 269
6 1615
7 12662
8 73528
9 836817
10 8476243
11 99348534
12 948849176
13 13193115597
14 177346261391
15 3684976294222
16 45021819481808
17 734808219625345
18 13524660020400771
19 290452222949307070
20 4639956700466396256
21 128621330002689008237
22 2735863084773695212719

List of values

[1, 3, 14, 48, 269, 1615, 12662, 73528, 836817, 8476243, 99348534, 948849176, 13193115597, 177346261391, 3684976294222, 45021819481808, 734808219625345, 13524660020400771, 290452222949307070, 4639956700466396256, 128621330002689008237, 2735863084773695212719]

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

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