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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 22 |
| 5 | 85 |
| 6 | 328 |
| 7 | 1253 |
| 8 | 4754 |
| 9 | 17994 |
| 10 | 68158 |
| 11 | 258808 |
| 12 | 985906 |
| 13 | 3768466 |
| 14 | 14451386 |
| 15 | 55585014 |
| 16 | 214377618 |
| 17 | 828795169 |
| 18 | 3211030684 |
| 19 | 12464308997 |
| 20 | 48465092366 |
| 21 | 188733879657 |
| 22 | 735977084412 |
| 23 | 2873525548315 |
| 24 | 11231884145434 |
| 25 | 43947466923095 |
| 26 | 172115939825516 |
[1,1,2,6,22,85,328,1253,4754,17994,68158,258808, 985906,3768466,14451386,55585014,214377618, 828795169,3211030684,12464308997,48465092366, 188733879657,735977084412,2873525548315, 11231884145434,43947466923095,172115939825516] |