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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 14 |
| 4 | 47 |
| 5 | 156 |
| 6 | 524 |
| 7 | 1800 |
| 8 | 6159 |
| 9 | 20999 |
| 10 | 71638 |
| 11 | 244608 |
| 12 | 835124 |
| 13 | 2850836 |
| 14 | 9732012 |
| 15 | 33223314 |
| 16 | 113417951 |
| 17 | 387185490 |
| 18 | 1321771895 |
| 19 | 4512261114 |
| 20 | 15403943682 |
| 21 | 52585931706 |
| 22 | 179517678728 |
| 23 | 612836866428 |
| 24 | 2092100497612 |
| 25 | 7142005837481 |
| 26 | 24381356169966 |
| 27 | 83232993999782 |
[1,3,14,47,156,524,1800,6159,20999,71638,244608, 835124,2850836,9732012,33223314,113417951, 387185490,1321771895,4512261114,15403943682, 52585931706,179517678728,612836866428, 2092100497612,7142005837481,24381356169966, 83232993999782] |