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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.

A380393 a(n) is the least k that has exactly n proper divisors d such that (-d)^k == -d (mod k).

Table of values

n a(n)
0 1
1 2
2 6
3 42
4 66
5 105
6 2805
7 561
8 1365
9 5005
10 5565
11 11305
12 36465
13 140505
14 239785
15 41041
16 682465
17 873145
18 185185
19 418285
20 1683969
21 2113665
22 5503785
23 1242241
24 6697405
25 8549905
26 31932901
27 11996985
28 31260405
29 30534805
30 47031061
31 825265
32 27265161
33 32306365
34 55336645
35 21662641
36 9276085
37 8964865

List of values

[1, 2, 6, 42, 66, 105, 2805, 561, 1365, 5005, 5565, 11305, 36465, 140505, 239785, 41041, 682465, 873145, 185185, 418285, 1683969, 2113665, 5503785, 1242241, 6697405, 8549905, 31932901, 11996985, 31260405, 30534805, 47031061, 825265, 27265161, 32306365, 55336645, 21662641, 9276085, 8964865]

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

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