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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 10 |
| 4 | 16 |
| 5 | 32 |
| 6 | 84 |
| 7 | 364 |
| 8 | 1408 |
| 9 | 7139 |
| 10 | 31239 |
| 11 | 217079 |
| 12 | 1318253 |
| 13 | 12282116 |
| 14 | 97242555 |
| 15 | 1151164326 |
| 16 | 12499753964 |
| 17 | 202416004411 |
| 18 | 2931538091352 |
| 19 | 63055463078232 |
| 20 | 1202866099324497 |
| 21 | 34468364489176178 |
[1,2,4,10,16,32,84,364,1408,7139,31239,217079, 1318253,12282116,97242555,1151164326,12499753964, 202416004411,2931538091352,63055463078232, 1202866099324497,34468364489176178] |