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.

A134156 a(n) = 2*tau(n) - n, where tau(n) is the number of divisors of n (A000005).

Table of values

n a(n)
1 1
2 2
3 1
4 2
5 -1
6 2
7 -3
8 0
9 -3
10 -2
11 -7
12 0
13 -9
14 -6
15 -7
16 -6
17 -13
18 -6
19 -15
20 -8
21 -13
22 -14
23 -19
24 -8
25 -19
26 -18
27 -19
28 -16
29 -25
30 -14
31 -27
32 -20
33 -25
34 -26
35 -27
36 -18
37 -33
38 -30
39 -31
40 -24
41 -37
42 -26
43 -39
44 -32
45 -33
46 -38
47 -43
48 -28
49 -43
50 -38
51 -43
52 -40
53 -49
54 -38
55 -47
56 -40
57 -49
58 -50
59 -55
60 -36

List of values

[1, 2, 1, 2, -1, 2, -3, 0, -3, -2, -7, 0, -9, -6, -7, -6, -13, -6, -15, -8, -13, -14, -19, -8, -19, -18, -19, -16, -25, -14, -27, -20, -25, -26, -27, -18, -33, -30, -31, -24, -37, -26, -39, -32, -33, -38, -43, -28, -43, -38, -43, -40, -49, -38, -47, -40, -49, -50, -55, -36]