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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 12 |
| 3 | 53 |
| 4 | 243 |
| 5 | 1141 |
| 6 | 5459 |
| 7 | 26346 |
| 8 | 128168 |
| 9 | 626971 |
| 10 | 3078529 |
| 11 | 15165364 |
| 12 | 74884171 |
| 13 | 370462126 |
| 14 | 1835612406 |
| 15 | 9106519567 |
| 16 | 45224396045 |
| 17 | 224785228719 |
| 18 | 1118079087396 |
| 19 | 5564712384177 |
| 20 | 27710087105226 |
| 21 | 138046537190474 |
| 22 | 687986650617224 |
| 23 | 3429877906752834 |
| 24 | 17104214087353510 |
| 25 | 85317456980257087 |
[1,3,12,53,243,1141,5459,26346,128168,626971, 3078529,15165364,74884171,370462126,1835612406, 9106519567,45224396045,224785228719,1118079087396, 5564712384177,27710087105226,138046537190474, 687986650617224,3429877906752834, 17104214087353510,85317456980257087] |