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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.

A293773 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/2, 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 -5
52 -5
53 -4
54 -1
55 1
56 4
57 5
58 6
59 6
60 5
61 3
62 2
63 -2
64 -3
65 -4
66 -5
67 -6
68 -6
69 -5
70 -3
71 0
72 6
73 7
74 7
75 6
76 4

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, -5, -5, -4, -1, 1, 4, 5, 6, 6, 5, 3, 2, -2, -3, -4, -5, -6, -6, -5, -3, 0, 6, 7, 7, 6, 4]

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