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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 45 |
| 4 | 161 |
| 5 | 899 |
| 6 | 4023 |
| 7 | 19387 |
| 8 | 92169 |
| 9 | 436539 |
| 10 | 2077281 |
| 11 | 9861263 |
| 12 | 46848707 |
| 13 | 222547181 |
| 14 | 1057107041 |
| 15 | 5021579939 |
| 16 | 23853406065 |
| 17 | 113308835575 |
| 18 | 538241104209 |
| 19 | 2556757711375 |
| 20 | 12145141483565 |
| 21 | 57691981461499 |
| 22 | 274049091332625 |
[1,7,45,161,899,4023,19387,92169,436539,2077281, 9861263,46848707,222547181,1057107041,5021579939, 23853406065,113308835575,538241104209, 2556757711375,12145141483565,57691981461499, 274049091332625] |