n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 5 |
4 | 26 |
5 | 110 |
6 | 490 |
7 | 2086 |
8 | 9240 |
9 | 40776 |
10 | 185820 |
11 | 855580 |
12 | 4048616 |
13 | 19455800 |
14 | 95773496 |
15 | 479581480 |
16 | 2454041920 |
17 | 12776826816 |
18 | 67849286160 |
19 | 366455145936 |
20 | 2015621873440 |
21 | 11268605368160 |
22 | 64074235576736 |
23 | 370040657037920 |
24 | 2171138049287296 |
25 | 12928631894588800 |
26 | 78139702237771200 |
[0,0,1,5,26,110,490,2086,9240,40776,185820,855580, 4048616,19455800,95773496,479581480,2454041920, 12776826816,67849286160,366455145936, 2015621873440,11268605368160,64074235576736, 370040657037920,2171138049287296, 12928631894588800,78139702237771200] |