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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 12 |
| 4 | 27 |
| 5 | 63 |
| 6 | 144 |
| 7 | 330 |
| 8 | 755 |
| 9 | 1728 |
| 10 | 3956 |
| 11 | 9057 |
| 12 | 20736 |
| 13 | 47474 |
| 14 | 108687 |
| 15 | 248832 |
| 16 | 569683 |
| 17 | 1304249 |
| 18 | 2985984 |
| 19 | 6836197 |
| 20 | 15650984 |
| 21 | 35831808 |
| 22 | 82034362 |
| 23 | 187811805 |
| 24 | 429981696 |
| 25 | 984412343 |
| 26 | 2253741659 |
| 27 | 5159780352 |
| 28 | 11812948115 |
| 29 | 27044899907 |
| 30 | 61917364224 |
[1,2,5,12,27,63,144,330,755,1728,3956,9057,20736, 47474,108687,248832,569683,1304249,2985984, 6836197,15650984,35831808,82034362,187811805, 429981696,984412343,2253741659,5159780352, 11812948115,27044899907,61917364224] |