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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 13 |
| 3 | 113 |
| 4 | 787 |
| 5 | 7428 |
| 6 | 62298 |
| 7 | 494579 |
| 8 | 3938849 |
| 9 | 31419870 |
| 10 | 250968250 |
| 11 | 2008718820 |
| 12 | 16085753439 |
| 13 | 128812555358 |
| 14 | 1031543802305 |
| 15 | 8260521035929 |
| 16 | 66148710544824 |
| 17 | 529714073173089 |
| 18 | 4241953681722567 |
| 19 | 33969698176325537 |
| 20 | 272030805637262923 |
[1,13,113,787,7428,62298,494579,3938849,31419870, 250968250,2008718820,16085753439,128812555358, 1031543802305,8260521035929,66148710544824, 529714073173089,4241953681722567, 33969698176325537,272030805637262923] |