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.

A143977 Rectangular array R by antidiagonals: label each unit square in the first quadrant lattice by its northeast vertex (x,y) and mark squares having |x-y| == 0 (mod 3); then R(m,n) is the number of marked squares in the rectangle [0,m] X [0,n].

Table of values

n a(n)
1 1
2 1
3 1
4 1
5 2
6 1
7 2
8 2
9 2
10 2
11 2
12 3
13 3
14 3
15 2
16 2
17 4
18 4
19 4
20 4
21 2
22 3
23 4
24 5
25 6
26 5
27 4
28 3
29 3
30 5
31 6
32 7
33 7
34 6
35 5
36 3
37 3
38 6
39 7
40 8
41 9
42 8
43 7
44 6
45 3
46 4
47 6
48 8
49 10
50 10
51 10
52 10
53 8
54 6
55 4
56 4
57 7
58 9
59 11
60 12
61 12
62 12
63 11
64 9
65 7
66 4
67 4
68 8
69 10
70 12
71 14
72 14
73 14
74 14
75 12
76 10
77 8
78 4
79 5
80 8
81 11
82 14
83 15
84 16
85 17
86 16
87 15
88 14
89 11
90 8
91 5

List of values

[1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 3, 3, 3, 2, 2, 4, 4, 4, 4, 2, 3, 4, 5, 6, 5, 4, 3, 3, 5, 6, 7, 7, 6, 5, 3, 3, 6, 7, 8, 9, 8, 7, 6, 3, 4, 6, 8, 10, 10, 10, 10, 8, 6, 4, 4, 7, 9, 11, 12, 12, 12, 11, 9, 7, 4, 4, 8, 10, 12, 14, 14, 14, 14, 12, 10, 8, 4, 5, 8, 11, 14, 15, 16, 17, 16, 15, 14, 11, 8, 5]