n | a(n) |
---|---|
0 | 1 |
1 | 6 |
2 | 30 |
3 | 144 |
4 | 666 |
5 | 3024 |
6 | 13476 |
7 | 59328 |
8 | 258354 |
9 | 1115856 |
10 | 4784508 |
11 | 20393856 |
12 | 86473548 |
13 | 365034816 |
14 | 1534827960 |
15 | 6431000832 |
16 | 26862228450 |
[1,6,30,144,666,3024,13476,59328,258354,1115856, 4784508,20393856,86473548,365034816,1534827960, 6431000832,26862228450] |