The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 32 |
| 5 | 109 |
| 6 | 419 |
| 7 | 1588 |
| 8 | 6394 |
| 9 | 25551 |
| 10 | 106210 |
| 11 | 438283 |
| 12 | 1863689 |
| 13 | 7875060 |
| 14 | 34040384 |
| 15 | 146360355 |
| 16 | 640715615 |
| 17 | 2791465710 |
| 18 | 12343656221 |
| 19 | 54346670390 |
| 20 | 242277534379 |
| 21 | 1075846812440 |
| 22 | 4828439923487 |
| 23 | 21592775822014 |
| 24 | 97458223274562 |
| 25 | 438426895287873 |
| 26 | 1988375049359820 |
| 27 | 8990333320807414 |
| 28 | 40943071427724043 |
[1,1,3,9,32,109,419,1588,6394,25551,106210,438283, 1863689,7875060,34040384,146360355,640715615, 2791465710,12343656221,54346670390,242277534379, 1075846812440,4828439923487,21592775822014, 97458223274562,438426895287873,1988375049359820, 8990333320807414,40943071427724043] |