n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 16 |
4 | 76 |
5 | 400 |
6 | 2356 |
7 | 15200 |
8 | 106644 |
9 | 806320 |
10 | 6526580 |
11 | 56231024 |
12 | 513207740 |
13 | 4941362512 |
14 | 50013751812 |
15 | 530481210672 |
16 | 5880285873060 |
17 | 67954587978448 |
18 | 816935340368068 |
19 | 10196643652651664 |
20 | 131904973822724540 |
21 | 1765645473517011568 |
22 | 24420203895517396180 |
[1,1,4,16,76,400,2356,15200,106644,806320,6526580, 56231024,513207740,4941362512,50013751812, 530481210672,5880285873060,67954587978448, 816935340368068,10196643652651664, 131904973822724540,1765645473517011568, 24420203895517396180] |