The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 18 |
| 3 | 62 |
| 4 | 193 |
| 5 | 558 |
| 6 | 1507 |
| 7 | 3828 |
| 8 | 9149 |
| 9 | 20609 |
| 10 | 43918 |
| 11 | 88960 |
| 12 | 172130 |
| 13 | 319637 |
| 14 | 572050 |
| 15 | 990413 |
| 16 | 1664308 |
| 17 | 2722302 |
| 18 | 4345275 |
| 19 | 6783191 |
| 20 | 10375943 |
| 21 | 15578976 |
| 22 | 22994469 |
| 23 | 33408938 |
| 24 | 47838207 |
| 25 | 67580783 |
| 26 | 94280764 |
| 27 | 130001506 |
| 28 | 177311376 |
| 29 | 239383023 |
[4,18,62,193,558,1507,3828,9149,20609,43918,88960, 172130,319637,572050,990413,1664308,2722302, 4345275,6783191,10375943,15578976,22994469, 33408938,47838207,67580783,94280764,130001506, 177311376,239383023] |