The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 3 |
| 6 | 6 |
| 7 | 11 |
| 8 | 20 |
| 9 | 37 |
| 10 | 68 |
| 11 | 125 |
| 12 | 230 |
| 13 | 423 |
| 14 | 778 |
| 15 | 1431 |
| 16 | 2632 |
| 17 | 4841 |
| 18 | 8904 |
| 19 | 16377 |
| 20 | 30122 |
| 21 | 55403 |
| 22 | 101902 |
| 23 | 187427 |
| 24 | 344732 |
| 25 | 634061 |
| 26 | 1166220 |
| 27 | 2145013 |
| 28 | 3945294 |
| 29 | 7256527 |
| 30 | 13346834 |
| 31 | 24548655 |
| 32 | 45152016 |
| 33 | 83047505 |
| 34 | 152748176 |
| 35 | 280947697 |
| 36 | 516743378 |
| 37 | 950439251 |
[0,1,0,1,2,3,6,11,20,37,68,125,230,423,778,1431, 2632,4841,8904,16377,30122,55403,101902,187427, 344732,634061,1166220,2145013,3945294,7256527, 13346834,24548655,45152016,83047505,152748176, 280947697,516743378,950439251] |