n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 4 |
3 | 11 |
4 | 28 |
5 | 152 |
6 | 726 |
7 | 5268 |
8 | 40438 |
9 | 365944 |
10 | 3628810 |
11 | 39974466 |
12 | 479001612 |
13 | 6228256404 |
14 | 87178339984 |
15 | 1307706805928 |
16 | 20922789888016 |
17 | 355688409760972 |
18 | 6402373705728018 |
19 | 121645133931170028 |
20 | 2432902008232456692 |
[1,2,4,11,28,152,726,5268,40438,365944,3628810, 39974466,479001612,6228256404,87178339984, 1307706805928,20922789888016,355688409760972, 6402373705728018,121645133931170028, 2432902008232456692] |