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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 7 |
| 4 | 32 |
| 5 | 68 |
| 6 | 320 |
| 7 | 747 |
| 8 | 3588 |
| 9 | 8884 |
| 10 | 43112 |
| 11 | 111054 |
| 12 | 542840 |
| 13 | 1439280 |
| 14 | 7068896 |
| 15 | 19157363 |
| 16 | 94420380 |
| 17 | 260343268 |
| 18 | 1286463464 |
| 19 | 3596962122 |
| 20 | 17809428792 |
| 21 | 50372422384 |
| 22 | 249792782560 |
| 23 | 713390782142 |
| 24 | 3542022471496 |
| 25 | 10199612069128 |
| 26 | 50692207741840 |
| 27 | 147016742815612 |
| 28 | 731273455228208 |
| 29 | 2134040173232352 |
[1,1,4,7,32,68,320,747,3588,8884,43112,111054, 542840,1439280,7068896,19157363,94420380, 260343268,1286463464,3596962122,17809428792, 50372422384,249792782560,713390782142, 3542022471496,10199612069128,50692207741840, 147016742815612,731273455228208,2134040173232352] |