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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | 8 |
| 4 | 46 |
| 5 | 252 |
| 6 | 1558 |
| 7 | 9800 |
| 8 | 64115 |
| 9 | 428546 |
| 10 | 2921527 |
| 11 | 20220128 |
| 12 | 141746372 |
| 13 | 1004278856 |
| 14 | 7180301580 |
| 15 | 51739691584 |
| 16 | 375370204876 |
| 17 | 2739615168344 |
| 18 | 20100885190508 |
| 19 | 148179065429664 |
| 20 | 1096966770610372 |
| 21 | 8151826588836472 |
| 22 | 60787793832205004 |
| 23 | 454719634089674432 |
[2,3,8,46,252,1558,9800,64115,428546,2921527, 20220128,141746372,1004278856,7180301580, 51739691584,375370204876,2739615168344, 20100885190508,148179065429664,1096966770610372, 8151826588836472,60787793832205004, 454719634089674432] |