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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 17 |
| 3 | 63 |
| 4 | 242 |
| 5 | 922 |
| 6 | 3502 |
| 7 | 13311 |
| 8 | 50608 |
| 9 | 192398 |
| 10 | 731429 |
| 11 | 2780649 |
| 12 | 10571120 |
| 13 | 40187929 |
| 14 | 152781292 |
| 15 | 580824261 |
| 16 | 2208102985 |
| 17 | 8394481949 |
| 18 | 31913061839 |
| 19 | 121322974122 |
| 20 | 461230079570 |
| 21 | 1753445197282 |
| 22 | 6666022438759 |
| 23 | 25342026784200 |
[1,5,17,63,242,922,3502,13311,50608,192398,731429, 2780649,10571120,40187929,152781292,580824261, 2208102985,8394481949,31913061839,121322974122, 461230079570,1753445197282,6666022438759, 25342026784200] |