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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 21 |
| 3 | 77 |
| 4 | 291 |
| 5 | 1119 |
| 6 | 3523 |
| 7 | 15007 |
| 8 | 50923 |
| 9 | 182669 |
| 10 | 701121 |
| 11 | 2379129 |
| 12 | 8909361 |
| 13 | 32490021 |
| 14 | 106309861 |
| 15 | 423990203 |
| 16 | 1456199483 |
| 17 | 5089398187 |
| 18 | 19942506259 |
| 19 | 65753622619 |
| 20 | 252337832801 |
| 21 | 903751067081 |
| 22 | 3026099773993 |
| 23 | 11771846189609 |
[1,5,21,77,291,1119,3523,15007,50923,182669, 701121,2379129,8909361,32490021,106309861, 423990203,1456199483,5089398187,19942506259, 65753622619,252337832801,903751067081, 3026099773993,11771846189609] |