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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 11 |
| 4 | 35 |
| 5 | 121 |
| 6 | 444 |
| 7 | 1689 |
| 8 | 6592 |
| 9 | 26258 |
| 10 | 106313 |
| 11 | 436203 |
| 12 | 1809727 |
| 13 | 7579202 |
| 14 | 31999297 |
| 15 | 136050472 |
| 16 | 582002281 |
| 17 | 2503242025 |
| 18 | 10818689627 |
| 19 | 46959246659 |
| 20 | 204623676444 |
| 21 | 894785832949 |
| 22 | 3925297799901 |
| 23 | 17270153317728 |
| 24 | 76187650017660 |
| 25 | 336934181461844 |
[1,2,4,11,35,121,444,1689,6592,26258,106313, 436203,1809727,7579202,31999297,136050472, 582002281,2503242025,10818689627,46959246659, 204623676444,894785832949,3925297799901, 17270153317728,76187650017660,336934181461844] |