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.

A127949 A000012 as an infinite lower triangular matrix with all 1's; A127899 = a simple transform; then A000012 * A127899. Given A051340, change all 1's to -1. Triangle read by rows, (n-1) -1's followed by "n".

Table of values

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

List of values

[1, -1, 2, -1, -1, 3, -1, -1, -1, 4, -1, -1, -1, -1, 5, -1, -1, -1, -1, -1, 6, -1, -1, -1, -1, -1, -1, 7, -1, -1, -1, -1, -1, -1, -1, 8, -1, -1, -1, -1, -1, -1, -1, -1, 9, -1, -1, -1, -1, -1, -1, -1, -1, -1, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 11, -1, -1, -1, -1, -1, -1]