| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 4 |
| 6 | 6 |
| 7 | 14 |
| 8 | 21 |
| 9 | 49 |
| 10 | 77 |
| 11 | 175 |
| 12 | 287 |
| 13 | 637 |
| 14 | 1079 |
| 15 | 2353 |
| 16 | 4082 |
| 17 | 8788 |
| 18 | 15522 |
| 19 | 33098 |
| 20 | 59280 |
| 21 | 125476 |
| 22 | 227240 |
| 23 | 478192 |
| 24 | 873886 |
| 25 | 1830270 |
| 26 | 3370030 |
| 27 | 7030570 |
| 28 | 13027730 |
| 29 | 27088870 |
| 30 | 50469890 |
| 31 | 104647630 |
| 32 | 195892565 |
| 33 | 405187825 |
| 34 | 761615285 |
| 35 | 1571990935 |
| 36 | 2965576715 |
[0,1,1,2,4,6,14,21,49,77,175,287,637,1079,2353, 4082,8788,15522,33098,59280,125476,227240,478192, 873886,1830270,3370030,7030570,13027730,27088870, 50469890,104647630,195892565,405187825,761615285, 1571990935,2965576715] |