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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 11 |
| 4 | 81 |
| 5 | 381 |
| 6 | 1673 |
| 7 | 8338 |
| 8 | 43585 |
| 9 | 220037 |
| 10 | 1086581 |
| 11 | 5401793 |
| 12 | 27090649 |
| 13 | 135792879 |
| 14 | 678626796 |
| 15 | 3389980516 |
| 16 | 16949548097 |
| 17 | 84773530931 |
| 18 | 423896384077 |
| 19 | 2119296824851 |
| 20 | 10596060837121 |
| 21 | 52981415499506 |
| 22 | 264911698225527 |
| 23 | 1324553898108366 |
| 24 | 6622726587716561 |
| 25 | 33113628115834381 |
| 26 | 165568491457714333 |
[1,1,1,11,81,381,1673,8338,43585,220037,1086581, 5401793,27090649,135792879,678626796,3389980516, 16949548097,84773530931,423896384077, 2119296824851,10596060837121,52981415499506, 264911698225527,1324553898108366,6622726587716561, 33113628115834381,165568491457714333] |