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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.

A318250 a(n) = (n - 1)! * sigma_2(n), where sigma_2(n) = sum of squares of divisors of n (A001157).

Table of values

n a(n)
1 1
2 5
3 20
4 126
5 624
6 6000
7 36000
8 428400
9 3669120
10 47174400
11 442713600
12 8382528000
13 81430272000
14 1556755200000
15 22666355712000
16 445916959488000
17 6067609067520000
18 161837779783680000
19 2317659281473536000
20 66418224823222272000
21 1216451004088320000000
22 31165474724742758400000

List of values

[1, 5, 20, 126, 624, 6000, 36000, 428400, 3669120, 47174400, 442713600, 8382528000, 81430272000, 1556755200000, 22666355712000, 445916959488000, 6067609067520000, 161837779783680000, 2317659281473536000, 66418224823222272000, 1216451004088320000000, 31165474724742758400000]

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

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