n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 6 |
3 | 18 |
4 | 122 |
5 | 600 |
6 | 3450 |
7 | 18914 |
8 | 107338 |
9 | 606816 |
10 | 3466356 |
11 | 19852470 |
12 | 114239642 |
13 | 659275760 |
14 | 3815952426 |
15 | 22138925718 |
16 | 128718762250 |
17 | 749773729952 |
18 | 4374616990332 |
19 | 25561798008252 |
20 | 149562047056572 |
21 | 876140945014640 |
22 | 5138089929141890 |
23 | 30162194533001982 |
[1,0,6,18,122,600,3450,18914,107338,606816, 3466356,19852470,114239642,659275760,3815952426, 22138925718,128718762250,749773729952, 4374616990332,25561798008252,149562047056572, 876140945014640,5138089929141890, 30162194533001982] |