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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 19 |
| 4 | 89 |
| 5 | 391 |
| 6 | 1817 |
| 7 | 8429 |
| 8 | 39697 |
| 9 | 187849 |
| 10 | 894965 |
| 11 | 4282191 |
| 12 | 20572961 |
| 13 | 99158645 |
| 14 | 479294877 |
| 15 | 2322365959 |
| 16 | 11276837761 |
| 17 | 54860498415 |
| 18 | 267336028565 |
| 19 | 1304677123305 |
| 20 | 6375749480369 |
| 21 | 31195075605755 |
| 22 | 152798541606529 |
| 23 | 749184538847397 |
| 24 | 3676699991008897 |
[1,1,5,19,89,391,1817,8429,39697,187849,894965, 4282191,20572961,99158645,479294877,2322365959, 11276837761,54860498415,267336028565, 1304677123305,6375749480369,31195075605755, 152798541606529,749184538847397,3676699991008897] |