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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.

A160620 a(n) = Sum_{d|n} phi(n/d)^2*2^d.

Table of values

n a(n)
0 0
1 2
2 6
3 16
4 28
5 64
6 96
7 200
8 320
9 616
10 1152
11 2248
12 4304
13 8480
14 16728
15 33152
16 66048
17 131584
18 263160
19 524936
20 1050176
21 2098240
22 4196952
23 8389576
24 16782976
25 33555744
26 67117920
27 134220712
28 268453360
29 536872480
30 1073780352
31 2147485448
32 4295034880
33 8589944384

List of values

[0, 2, 6, 16, 28, 64, 96, 200, 320, 616, 1152, 2248, 4304, 8480, 16728, 33152, 66048, 131584, 263160, 524936, 1050176, 2098240, 4196952, 8389576, 16782976, 33555744, 67117920, 134220712, 268453360, 536872480, 1073780352, 2147485448, 4295034880, 8589944384]

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

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