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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 33 |
| 4 | 153 |
| 5 | 636 |
| 6 | 3007 |
| 7 | 13250 |
| 8 | 63327 |
| 9 | 288054 |
| 10 | 1386855 |
| 11 | 6435925 |
| 12 | 31148163 |
| 13 | 146526132 |
| 14 | 711937705 |
| 15 | 3381965649 |
| 16 | 16482630633 |
| 17 | 78873855946 |
| 18 | 385353116887 |
| 19 | 1854488970539 |
| 20 | 9078781409403 |
| 21 | 43887735905676 |
| 22 | 215218942867197 |
| 23 | 1044179619918984 |
| 24 | 5127856710554269 |
| 25 | 24953490798050234 |
| 26 | 122695363704248793 |
[1,2,9,33,153,636,3007,13250,63327,288054,1386855, 6435925,31148163,146526132,711937705,3381965649, 16482630633,78873855946,385353116887, 1854488970539,9078781409403,43887735905676, 215218942867197,1044179619918984,5127856710554269, 24953490798050234,122695363704248793] |