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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 8 |
| 3 | 14 |
| 4 | 25 |
| 5 | 48 |
| 6 | 99 |
| 7 | 215 |
| 8 | 482 |
| 9 | 1100 |
| 10 | 2534 |
| 11 | 5865 |
| 12 | 13606 |
| 13 | 31599 |
| 14 | 73425 |
| 15 | 170656 |
| 16 | 396688 |
| 17 | 922146 |
| 18 | 2143685 |
| 19 | 4983416 |
| 20 | 11584987 |
| 21 | 26931775 |
| 22 | 62608726 |
| 23 | 145547572 |
| 24 | 338356994 |
| 25 | 786584517 |
| 26 | 1828587086 |
| 27 | 4250949167 |
| 28 | 9882257793 |
| 29 | 22973462076 |
| 30 | 53406819752 |
| 31 | 124155792838 |
[4,8,14,25,48,99,215,482,1100,2534,5865,13606, 31599,73425,170656,396688,922146,2143685,4983416, 11584987,26931775,62608726,145547572,338356994, 786584517,1828587086,4250949167,9882257793, 22973462076,53406819752,124155792838] |