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.

A361987 a(1) = 1; a(n) = n^2 * Sum_{d|n, d < n} (-1)^(n/d) a(d) / d^2.

Table of values

n a(n)
1 1
2 4
3 -9
4 32
5 -25
6 -36
7 -49
8 256
9 0
10 -100
11 -121
12 -288
13 -169
14 -196
15 225
16 2048
17 -289
18 0
19 -361
20 -800
21 441
22 -484
23 -529
24 -2304
25 0
26 -676
27 0
28 -1568
29 -841
30 900
31 -961
32 16384
33 1089
34 -1156
35 1225
36 0
37 -1369
38 -1444
39 1521
40 -6400
41 -1681
42 1764
43 -1849
44 -3872
45 0
46 -2116
47 -2209
48 -18432
49 0
50 0
51 2601
52 -5408
53 -2809
54 0

List of values

[1, 4, -9, 32, -25, -36, -49, 256, 0, -100, -121, -288, -169, -196, 225, 2048, -289, 0, -361, -800, 441, -484, -529, -2304, 0, -676, 0, -1568, -841, 900, -961, 16384, 1089, -1156, 1225, 0, -1369, -1444, 1521, -6400, -1681, 1764, -1849, -3872, 0, -2116, -2209, -18432, 0, 0, 2601, -5408, -2809, 0]