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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 32 |
| 5 | 110 |
| 6 | 444 |
| 7 | 1676 |
| 8 | 7090 |
| 9 | 28314 |
| 10 | 121990 |
| 11 | 504920 |
| 12 | 2212372 |
| 13 | 9382416 |
| 14 | 41584876 |
| 15 | 179539056 |
| 16 | 803135830 |
| 17 | 3514731918 |
| 18 | 15837959224 |
| 19 | 70054928916 |
| 20 | 317581225854 |
| 21 | 1416879893330 |
| 22 | 6455464123356 |
| 23 | 29006054220056 |
| 24 | 132718076206868 |
| 25 | 599896260799838 |
| 26 | 2754895622501684 |
| 27 | 12515550063373760 |
| 28 | 57657852586593046 |
[1,1,3,8,32,110,444,1676,7090,28314,121990,504920, 2212372,9382416,41584876,179539056,803135830, 3514731918,15837959224,70054928916,317581225854, 1416879893330,6455464123356,29006054220056, 132718076206868,599896260799838,2754895622501684, 12515550063373760,57657852586593046] |