| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 1 |
| 3 | 5 |
| 4 | 4 |
| 5 | 13 |
| 6 | 30 |
| 7 | 43 |
| 8 | 129 |
| 9 | 245 |
| 10 | 519 |
| 11 | 1254 |
| 12 | 2525 |
| 13 | 5707 |
| 14 | 12749 |
| 15 | 27205 |
| 16 | 60962 |
| 17 | 133639 |
| 18 | 292125 |
| 19 | 647249 |
| 20 | 1418245 |
| 21 | 3119874 |
| 22 | 6875729 |
| 23 | 15098235 |
| 24 | 33237465 |
| 25 | 73128441 |
| 26 | 160782286 |
| 27 | 353832779 |
| 28 | 778266279 |
| 29 | 1711882901 |
| 30 | 3766329669 |
| 31 | 8284438272 |
[2,1,5,4,13,30,43,129,245,519,1254,2525,5707, 12749,27205,60962,133639,292125,647249,1418245, 3119874,6875729,15098235,33237465,73128441, 160782286,353832779,778266279,1711882901, 3766329669,8284438272] |