n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 18 |
3 | 52 |
4 | 392 |
5 | 1616 |
6 | 9504 |
7 | 44864 |
8 | 241792 |
9 | 1201408 |
10 | 6271488 |
11 | 31765504 |
12 | 163874816 |
13 | 835997696 |
14 | 4293992448 |
15 | 21963948032 |
16 | 112631775232 |
17 | 576686718976 |
18 | 2955481841664 |
19 | 15137951186944 |
20 | 77563611840512 |
21 | 397334442672128 |
[1,1,18,52,392,1616,9504,44864,241792,1201408, 6271488,31765504,163874816,835997696,4293992448, 21963948032,112631775232,576686718976, 2955481841664,15137951186944,77563611840512, 397334442672128] |