n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 4 |
3 | 16 |
4 | 66 |
5 | 438 |
6 | 2694 |
7 | 25296 |
8 | 204576 |
9 | 2509728 |
10 | 24912816 |
11 | 381010320 |
12 | 4440815472 |
13 | 82150191264 |
14 | 1089159690912 |
15 | 23879423005440 |
16 | 351430312958208 |
17 | 9005004020293632 |
18 | 144184020764472576 |
19 | 4277182103330660352 |
20 | 73227226213747521792 |
21 | 2499666592623881921280 |
[1,2,4,16,66,438,2694,25296,204576,2509728, 24912816,381010320,4440815472,82150191264, 1089159690912,23879423005440,351430312958208, 9005004020293632,144184020764472576, 4277182103330660352,73227226213747521792, 2499666592623881921280] |