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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 14 |
| 4 | 44 |
| 5 | 158 |
| 6 | 663 |
| 7 | 3310 |
| 8 | 19759 |
| 9 | 139660 |
| 10 | 1147120 |
| 11 | 10729684 |
| 12 | 112309193 |
| 13 | 1297522650 |
| 14 | 16371057801 |
| 15 | 223716758346 |
| 16 | 3289199827236 |
| 17 | 51745234494858 |
| 18 | 867023125576027 |
| 19 | 15411557297930534 |
| 20 | 289610871340870883 |
| 21 | 5736017561257017128 |
| 22 | 119413599371241577016 |
[1,2,5,14,44,158,663,3310,19759,139660,1147120, 10729684,112309193,1297522650,16371057801, 223716758346,3289199827236,51745234494858, 867023125576027,15411557297930534, 289610871340870883,5736017561257017128, 119413599371241577016] |