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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 14 |
| 3 | 47 |
| 4 | 156 |
| 5 | 548 |
| 6 | 1970 |
| 7 | 7049 |
| 8 | 25364 |
| 9 | 91307 |
| 10 | 328700 |
| 11 | 1183518 |
| 12 | 4261468 |
| 13 | 15344635 |
| 14 | 55253618 |
| 15 | 198959548 |
| 16 | 716424463 |
| 17 | 2579743890 |
| 18 | 9289300111 |
| 19 | 33449490192 |
| 20 | 120447025154 |
| 21 | 433713239426 |
| 22 | 1561742028021 |
| 23 | 5623619418043 |
| 24 | 20249884464928 |
[4,14,47,156,548,1970,7049,25364,91307,328700, 1183518,4261468,15344635,55253618,198959548, 716424463,2579743890,9289300111,33449490192, 120447025154,433713239426,1561742028021, 5623619418043,20249884464928] |