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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.

A375054 Let M(n,x) denote the Maclaurin polynomial of degree 2n for cos x. Let u(n) be the number of nonreal zeros of M(n,x) and v(n) the number of real zeros of M(n,x). Then a(n) = u(n) - v(n).

Table of values

n a(n)
1 -2
2 -4
3 2
4 0
5 6
6 4
7 2
8 8
9 6
10 4
11 10
12 8
13 14
14 12
15 10
16 16
17 14
18 12
19 18
20 16
21 22
22 20
23 18
24 24
25 22
26 28
27 26
28 24
29 30
30 28
31 26
32 32
33 30
34 36
35 34
36 32
37 38
38 36
39 34
40 40
41 38
42 44
43 42
44 40
45 46
46 44
47 50
48 48
49 46
50 52
51 50
52 48
53 54
54 52
55 58
56 56
57 54
58 60
59 58
60 64
61 62
62 60
63 66
64 64
65 62
66 68
67 66

List of values

[-2, -4, 2, 0, 6, 4, 2, 8, 6, 4, 10, 8, 14, 12, 10, 16, 14, 12, 18, 16, 22, 20, 18, 24, 22, 28, 26, 24, 30, 28, 26, 32, 30, 36, 34, 32, 38, 36, 34, 40, 38, 44, 42, 40, 46, 44, 50, 48, 46, 52, 50, 48, 54, 52, 58, 56, 54, 60, 58, 64, 62, 60, 66, 64, 62, 68, 66]

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