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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 13 |
| 2 | 130 |
| 3 | 1106 |
| 4 | 8575 |
| 5 | 62475 |
| 6 | 435576 |
| 7 | 2939208 |
| 8 | 19342285 |
| 9 | 124800361 |
| 10 | 792586270 |
| 11 | 4969028750 |
| 12 | 30822650251 |
| 13 | 189500937303 |
| 14 | 1156406300340 |
| 15 | 7012380492516 |
| 16 | 42294614785465 |
| 17 | 253926386816725 |
| 18 | 1518506730836026 |
| 19 | 9050029200532298 |
| 20 | 53778595325886295 |
| 21 | 318762380704793571 |
| 22 | 1885254096749834160 |
[1,13,130,1106,8575,62475,435576,2939208,19342285, 124800361,792586270,4969028750,30822650251, 189500937303,1156406300340,7012380492516, 42294614785465,253926386816725,1518506730836026, 9050029200532298,53778595325886295, 318762380704793571,1885254096749834160] |