| n | a(n) |
|---|---|
| 1 | 13 |
| 2 | 117 |
| 3 | 761 |
| 4 | 5105 |
| 5 | 31525 |
| 6 | 177421 |
| 7 | 937817 |
| 8 | 4803653 |
| 9 | 24257725 |
| 10 | 121800949 |
| 11 | 610147053 |
| 12 | 3053493273 |
| 13 | 15274472475 |
| 14 | 76391277073 |
| 15 | 382008613455 |
| 16 | 1910192140573 |
| 17 | 9551389260819 |
| 18 | 47758200502193 |
| 19 | 238794678323345 |
| 20 | 1193984277090533 |
[13,117,761,5105,31525,177421,937817,4803653, 24257725,121800949,610147053,3053493273, 15274472475,76391277073,382008613455, 1910192140573,9551389260819,47758200502193, 238794678323345,1193984277090533] |