The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 11 |
| 5 | 18 |
| 6 | 30 |
| 7 | 45 |
| 8 | 101 |
| 9 | 171 |
| 10 | 483 |
| 11 | 702 |
| 12 | 2745 |
| 13 | 3406 |
| 14 | 21215 |
| 15 | 23237 |
| 16 | 202627 |
| 17 | 205701 |
| 18 | 2169260 |
| 19 | 2138431 |
| 20 | 24770064 |
| 21 | 24197219 |
| 22 | 294389605 |
| 23 | 286927242 |
| 24 | 3600713132 |
| 25 | 3508785697 |
| 26 | 45050653316 |
| 27 | 43916201874 |
| 28 | 574363373312 |
[1,1,2,5,11,18,30,45,101,171,483,702,2745,3406, 21215,23237,202627,205701,2169260,2138431, 24770064,24197219,294389605,286927242,3600713132, 3508785697,45050653316,43916201874,574363373312] |