n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 17 |
4 | 120 |
5 | 884 |
6 | 6558 |
7 | 48680 |
8 | 361422 |
9 | 2683328 |
10 | 19922214 |
11 | 147910952 |
12 | 1098154590 |
13 | 8153170064 |
14 | 60532632918 |
15 | 449420225720 |
16 | 3336688521102 |
17 | 24773006668448 |
18 | 183925426722054 |
19 | 1365541253642312 |
20 | 10138363949208510 |
21 | 75271562311604144 |
[1,4,17,120,884,6558,48680,361422,2683328, 19922214,147910952,1098154590,8153170064, 60532632918,449420225720,3336688521102, 24773006668448,183925426722054,1365541253642312, 10138363949208510,75271562311604144] |