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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 25 |
| 5 | 80 |
| 6 | 271 |
| 7 | 952 |
| 8 | 3443 |
| 9 | 12758 |
| 10 | 48212 |
| 11 | 185283 |
| 12 | 722227 |
| 13 | 2849955 |
| 14 | 11366379 |
| 15 | 45757142 |
| 16 | 185726603 |
| 17 | 759401542 |
| 18 | 3125472832 |
| 19 | 12939604503 |
| 20 | 53856950922 |
| 21 | 225250407802 |
| 22 | 946253665230 |
| 23 | 3991221520996 |
| 24 | 16897320866269 |
| 25 | 71782331694315 |
[1,1,3,8,25,80,271,952,3443,12758,48212,185283, 722227,2849955,11366379,45757142,185726603, 759401542,3125472832,12939604503,53856950922, 225250407802,946253665230,3991221520996, 16897320866269,71782331694315] |