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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 16 |
| 6 | 61 |
| 7 | 259 |
| 8 | 1228 |
| 9 | 6284 |
| 10 | 34564 |
| 11 | 201978 |
| 12 | 1246652 |
| 13 | 8084728 |
| 14 | 54862377 |
| 15 | 388266809 |
| 16 | 2857708840 |
| 17 | 21822753453 |
| 18 | 172550972216 |
| 19 | 1410144139982 |
| 20 | 11892084248959 |
| 21 | 103343300813517 |
| 22 | 924223611649636 |
| 23 | 8496346816801059 |
| 24 | 80201063980292729 |
| 25 | 776585923239589681 |
| 26 | 7706568335863727817 |
| 27 | 78311132374535936605 |
[1,1,1,2,5,16,61,259,1228,6284,34564,201978, 1246652,8084728,54862377,388266809,2857708840, 21822753453,172550972216,1410144139982, 11892084248959,103343300813517,924223611649636, 8496346816801059,80201063980292729, 776585923239589681,7706568335863727817, 78311132374535936605] |