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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.

A293681 Let P be the sequence of distinct lattice points defined by the following rules: P(1) = (0,0), P(2) = (1,0), and for any i < j < k, P(k) does not lie on the vector (P(i), P(j)), and for any n > 2, P(n) is the closest lattice point to P(n-1) such that the angle of the vectors (P(n-2), P(n-1)) and (P(n-1), P(n)), say t, satisfies 0 < t < Pi, and in case of a tie, minimize the angle t; a(n) = Y-coordinate of P(n).

Table of values

n a(n)
1 0
2 0
3 1
4 1
5 0
6 -1
7 -1
8 0
9 1
10 2
11 2
12 1
13 -1
14 -2
15 -2
16 -1
17 1
18 2
19 3
20 3
21 2
22 1
23 -1
24 -2
25 -3
26 -3
27 -2
28 -1
29 2
30 3
31 4
32 4
33 3
34 1
35 0
36 -1
37 -3
38 -4
39 -4
40 -3
41 -2
42 0
43 4
44 5
45 5
46 4
47 2
48 -1
49 -2
50 -3
51 0
52 0
53 -1
54 -3
55 -4
56 -5
57 -5
58 -4
59 -3
60 -1
61 -5
62 -6
63 -6
64 -5
65 -3
66 0
67 4
68 5
69 6
70 6
71 5
72 3
73 -1
74 -2
75 -3

List of values

[0, 0, 1, 1, 0, -1, -1, 0, 1, 2, 2, 1, -1, -2, -2, -1, 1, 2, 3, 3, 2, 1, -1, -2, -3, -3, -2, -1, 2, 3, 4, 4, 3, 1, 0, -1, -3, -4, -4, -3, -2, 0, 4, 5, 5, 4, 2, -1, -2, -3, 0, 0, -1, -3, -4, -5, -5, -4, -3, -1, -5, -6, -6, -5, -3, 0, 4, 5, 6, 6, 5, 3, -1, -2, -3]