The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 2 |
| 4 | 2 |
| 5 | 3 |
| 6 | 4 |
| 7 | 7 |
| 8 | 10 |
| 9 | 16 |
| 10 | 30 |
| 11 | 51 |
| 12 | 88 |
| 13 | 153 |
| 14 | 277 |
| 15 | 509 |
| 16 | 905 |
| 17 | 1660 |
| 18 | 3079 |
| 19 | 5535 |
| 20 | 10234 |
| 21 | 19053 |
[1,2,2,2,3,4,7,10,16,30,51,88,153,277,509,905, 1660,3079,5535,10234,19053] |