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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 72 |
| 4 | 577 |
| 5 | 4617 |
| 6 | 36936 |
| 7 | 295489 |
| 8 | 2363913 |
| 9 | 18911304 |
| 10 | 151290433 |
| 11 | 1210323465 |
| 12 | 9682587720 |
| 13 | 77460701761 |
| 14 | 619685614089 |
| 15 | 4957484912712 |
| 16 | 39659879301697 |
| 17 | 317279034413577 |
| 18 | 2538232275308616 |
[1,9,72,577,4617,36936,295489,2363913,18911304, 151290433,1210323465,9682587720,77460701761, 619685614089,4957484912712,39659879301697, 317279034413577,2538232275308616] |