n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 9 |
3 | 52 |
4 | 340 |
5 | 2394 |
6 | 17710 |
7 | 135720 |
8 | 1068012 |
9 | 8579560 |
10 | 70068713 |
11 | 580034052 |
12 | 4855986044 |
13 | 41043559340 |
14 | 349756577100 |
15 | 3001701610320 |
16 | 25921837477692 |
17 | 225083787458904 |
18 | 1963988670706228 |
19 | 17211860478150800 |
20 | 151433425446423120 |
[1,2,9,52,340,2394,17710,135720,1068012,8579560, 70068713,580034052,4855986044,41043559340, 349756577100,3001701610320,25921837477692, 225083787458904,1963988670706228, 17211860478150800,151433425446423120] |