| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 512 |
| 2 | 1021020 |
| 3 | 2399141888 |
| 4 | 6016814703900 |
| 5 | 15626259253952512 |
| 6 | 41477110789150966020 |
| 7 | 111745115394167694950400 |
| 8 | 304331361887290342345862940 |
| 9 | 835666006020766806513664655360 |
| 10 | 2309513382640863232775760738593520 |
| 11 | 6416034331756986890806503962421755904 |
[1,512,1021020,2399141888,6016814703900, 15626259253952512,41477110789150966020, 111745115394167694950400, 304331361887290342345862940, 835666006020766806513664655360, 2309513382640863232775760738593520, 6416034331756986890806503962421755904] |