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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 60 |
| 3 | 1562 |
| 4 | 29907 |
| 5 | 707903 |
| 6 | 15859323 |
| 7 | 354859954 |
| 8 | 8061851335 |
| 9 | 181382499259 |
| 10 | 4095897476480 |
| 11 | 92476840837163 |
| 12 | 2086314577400136 |
| 13 | 47096964973772265 |
| 14 | 1062921614745008697 |
| 15 | 23989328157229264043 |
| 16 | 541446343762904191567 |
| 17 | 12220135872229640539724 |
[1,3,60,1562,29907,707903,15859323,354859954, 8061851335,181382499259,4095897476480, 92476840837163,2086314577400136,47096964973772265, 1062921614745008697,23989328157229264043, 541446343762904191567,12220135872229640539724] |