| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 3 |
| 6 | 8 |
| 7 | 25 |
| 8 | 64 |
| 9 | 148 |
| 10 | 356 |
| 11 | 826 |
| 12 | 1863 |
| 13 | 4205 |
| 14 | 9246 |
| 15 | 19865 |
| 16 | 42935 |
| 17 | 90872 |
| 18 | 190561 |
| 19 | 399104 |
| 20 | 829883 |
| 21 | 1710609 |
| 22 | 3523315 |
| 23 | 7224223 |
| 24 | 14755538 |
| 25 | 30092167 |
| 26 | 61177910 |
| 27 | 124028647 |
| 28 | 251168840 |
| 29 | 507216174 |
| 30 | 1022829206 |
| 31 | 2061466047 |
| 32 | 4149639752 |
[0,0,0,0,1,3,8,25,64,148,356,826,1863,4205,9246, 19865,42935,90872,190561,399104,829883,1710609, 3523315,7224223,14755538,30092167,61177910, 124028647,251168840,507216174,1022829206, 2061466047,4149639752] |