The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 7 |
| 6 | 14 |
| 7 | 27 |
| 8 | 55 |
| 9 | 111 |
| 10 | 232 |
| 11 | 486 |
| 12 | 1039 |
| 13 | 2226 |
| 14 | 4820 |
| 15 | 10449 |
| 16 | 22727 |
| 17 | 49354 |
| 18 | 107117 |
| 19 | 231774 |
| 20 | 500040 |
[1,1,1,2,4,7,14,27,55,111,232,486,1039,2226,4820, 10449,22727,49354,107117,231774,500040] |