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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 22 |
| 4 | 127 |
| 5 | 474 |
| 6 | 1574 |
| 7 | 6008 |
| 8 | 25773 |
| 9 | 107883 |
| 10 | 427351 |
| 11 | 1669801 |
| 12 | 6643782 |
| 13 | 26789257 |
| 14 | 107746282 |
| 15 | 430470899 |
| 16 | 1717012749 |
| 17 | 6863694378 |
| 18 | 27481113638 |
| 19 | 109996928003 |
| 20 | 439924466026 |
| 21 | 1759098789526 |
| 22 | 7035859329512 |
| 23 | 28146676447417 |
| 24 | 112595619434887 |
| 25 | 450374698997499 |
[1,1,2,22,127,474,1574,6008,25773,107883,427351, 1669801,6643782,26789257,107746282,430470899, 1717012749,6863694378,27481113638,109996928003, 439924466026,1759098789526,7035859329512, 28146676447417,112595619434887,450374698997499] |