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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 35 |
| 4 | 202 |
| 5 | 1271 |
| 6 | 8463 |
| 7 | 58639 |
| 8 | 418419 |
| 9 | 3053702 |
| 10 | 22687372 |
| 11 | 171008336 |
| 12 | 1304491048 |
| 13 | 10051505234 |
| 14 | 78117049696 |
| 15 | 611612430537 |
| 16 | 4819607926076 |
| 17 | 38195797609995 |
| 18 | 304234734698412 |
[1,2,7,35,202,1271,8463,58639,418419,3053702, 22687372,171008336,1304491048,10051505234, 78117049696,611612430537,4819607926076, 38195797609995,304234734698412] |