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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 52 |
| 6 | 178 |
| 7 | 625 |
| 8 | 2229 |
| 9 | 8292 |
| 10 | 31844 |
| 11 | 123850 |
| 12 | 487577 |
| 13 | 1939259 |
| 14 | 7783926 |
| 15 | 31652369 |
| 16 | 130184871 |
| 17 | 539206880 |
| 18 | 2246282327 |
| 19 | 9408346891 |
| 20 | 39623252299 |
| 21 | 167927239399 |
| 22 | 715732297981 |
| 23 | 3063454084931 |
| 24 | 13158541339027 |
| 25 | 56712257652225 |
| 26 | 245295621094005 |
| 27 | 1064945938445083 |
| 28 | 4639147279079300 |
[1,1,2,5,16,52,178,625,2229,8292,31844,123850, 487577,1939259,7783926,31652369,130184871, 539206880,2246282327,9408346891,39623252299, 167927239399,715732297981,3063454084931, 13158541339027,56712257652225,245295621094005, 1064945938445083,4639147279079300] |