cp's OEIS Frontend

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.

A038843 Unitary superperfect numbers: numbers n such that usigma(usigma(n)) = 2*n, where usigma(n) is the sum of unitary divisors of n (A034448).

Table of values

n a(n)
1 2
2 9
3 165
4 238
5 1640
6 4320
7 10250
8 10824
9 13500
10 23760
11 58500
12 66912
13 425880
14 520128
15 873180
16 931392
17 1899744
18 2129400
19 2253888
20 3276000
21 4580064
22 4668300
23 13722800
24 15459840
25 40360320
26 201801600
27 439021440
28 3809332800
29 15359485680
30 794436968640
31 1407035080704

List of values

[2, 9, 165, 238, 1640, 4320, 10250, 10824, 13500, 23760, 58500, 66912, 425880, 520128, 873180, 931392, 1899744, 2129400, 2253888, 3276000, 4580064, 4668300, 13722800, 15459840, 40360320, 201801600, 439021440, 3809332800, 15359485680, 794436968640, 1407035080704]

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

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