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.

A123191 Triangle read by rows: T(n,k) is the coefficient of x^k in the polynomial P[n] defined by P[0]=1, P[1]=x-1, P[n]=(1-x)P[n-1]+xP[n-2] for n>=2. Alternatively, P[n]=-1-(-x)^n-3*Sum((-x)^k,k=1..n-1).

Table of values

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

List of values

[1, -1, 1, -1, 3, -1, -1, 3, -3, 1, -1, 3, -3, 3, -1, -1, 3, -3, 3, -3, 1, -1, 3, -3, 3, -3, 3, -1, -1, 3, -3, 3, -3, 3, -3, 1, -1, 3, -3, 3, -3, 3, -3, 3, -1, -1, 3, -3, 3, -3, 3, -3, 3, -3, 1, -1, 3, -3, 3, -3, 3, -3, 3, -3, 3, -1]