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.

A173424 Triangle read by rows: T(n, k) = (2*n - 2*k)!*(2*k)!/(2^n*(n - k)!*k!).

Table of values

n a(n)
0 1
1 1
2 1
3 3
4 1
5 3
6 15
7 3
8 3
9 15
10 105
11 15
12 9
13 15
14 105
15 945
16 105
17 45
18 45
19 105
20 945
21 10395
22 945
23 315
24 225
25 315
26 945
27 10395
28 135135
29 10395
30 2835
31 1575
32 1575
33 2835
34 10395
35 135135
36 2027025
37 135135
38 31185
39 14175
40 11025
41 14175
42 31185
43 135135
44 2027025
45 34459425

List of values

[1, 1, 1, 3, 1, 3, 15, 3, 3, 15, 105, 15, 9, 15, 105, 945, 105, 45, 45, 105, 945, 10395, 945, 315, 225, 315, 945, 10395, 135135, 10395, 2835, 1575, 1575, 2835, 10395, 135135, 2027025, 135135, 31185, 14175, 11025, 14175, 31185, 135135, 2027025, 34459425]