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.

A049689 a(n)=Sum{((-1)^(i+1))*T(i,n-i): i=0,1,...,n}, array T as in A049687.

Table of values

n a(n)
0 0
1 0
2 1
3 0
4 3
5 0
6 5
7 0
8 9
9 0
10 13
11 0
12 17
13 0
14 23
15 0
16 31
17 0
18 37
19 0
20 45
21 0
22 55
23 0
24 63
25 0
26 75
27 0
28 87
29 0
30 95
31 0
32 111
33 0
34 127
35 0
36 139
37 0
38 157
39 0
40 173
41 0

List of values

[0, 0, 1, 0, 3, 0, 5, 0, 9, 0, 13, 0, 17, 0, 23, 0, 31, 0, 37, 0, 45, 0, 55, 0, 63, 0, 75, 0, 87, 0, 95, 0, 111, 0, 127, 0, 139, 0, 157, 0, 173, 0]