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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 20 |
| 6 | 48 |
| 7 | 136 |
| 8 | 360 |
| 9 | 1040 |
| 10 | 2944 |
| 11 | 8704 |
| 12 | 25280 |
| 13 | 76320 |
| 14 | 226720 |
| 15 | 692992 |
| 16 | 2096640 |
| 17 | 6470016 |
| 18 | 19799936 |
| 19 | 61713152 |
| 20 | 190683520 |
| 21 | 598033152 |
| 22 | 1863995392 |
| 23 | 5879859200 |
| 24 | 18438913536 |
| 25 | 58464724992 |
| 26 | 184356152832 |
| 27 | 586898946048 |
| 28 | 1859875518464 |
| 29 | 5941384080384 |
| 30 | 18901502482432 |
[1,2,4,8,20,48,136,360,1040,2944,8704,25280,76320, 226720,692992,2096640,6470016,19799936,61713152, 190683520,598033152,1863995392,5879859200, 18438913536,58464724992,184356152832,586898946048, 1859875518464,5941384080384,18901502482432] |