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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.

A307642 a(n) = n!*Sum_{i=1..n} (Sum_{j=1..i} (i/j)).

Table of values

n a(n)
1 1
2 8
3 57
4 428
5 3510
6 31644
7 312984
8 3380544
9 39664080
10 502927200
11 6858181440
12 100135491840
13 1559197261440
14 25797280723200
15 452046655872000
16 8364495012249600
17 162994310248089600
18 3336683369519001600
19 71596721810396160000
20 1606993396943155200000

List of values

[1, 8, 57, 428, 3510, 31644, 312984, 3380544, 39664080, 502927200, 6858181440, 100135491840, 1559197261440, 25797280723200, 452046655872000, 8364495012249600, 162994310248089600, 3336683369519001600, 71596721810396160000, 1606993396943155200000]

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

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