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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 105 |
| 4 | 5005 |
| 5 | 85085 |
| 6 | 1616615 |
| 7 | 37182145 |
| 8 | 6685349671 |
| 9 | 247357937827 |
| 10 | 10141675450907 |
| 11 | 436092044389001 |
| 12 | 20496326086283047 |
| 13 | 9156001667401012567 |
| 14 | 558516101711461766587 |
| 15 | 37420578814667938361329 |
| 16 | 2656861095841423623654359 |
| 17 | 193950859996423924526768207 |
| 18 | 15322117939717490037614688353 |
| 19 | 1271735788996551673122019133299 |
[1,2,6,105,5005,85085,1616615,37182145,6685349671, 247357937827,10141675450907,436092044389001, 20496326086283047,9156001667401012567, 558516101711461766587,37420578814667938361329, 2656861095841423623654359, 193950859996423924526768207, 15322117939717490037614688353, 1271735788996551673122019133299] |