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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 5448 |
| 3 | 517971 |
| 4 | 10388788 |
| 5 | 97809616 |
| 6 | 587267282 |
| 7 | 2615047418 |
| 8 | 9408671330 |
| 9 | 28851490163 |
| 10 | 78132541528 |
| 11 | 191563698893 |
| 12 | 432971108530 |
| 13 | 914435915008 |
| 14 | 1823570327812 |
| 15 | 3461969170632 |
| 16 | 6297974185728 |
| 17 | 11037428544793 |
| 18 | 18716682230144 |
| 19 | 30822735206253 |
| 20 | 49446074607790 |
[0,1,5448,517971,10388788,97809616,587267282, 2615047418,9408671330,28851490163,78132541528, 191563698893,432971108530,914435915008, 1823570327812,3461969170632,6297974185728, 11037428544793,18716682230144,30822735206253, 49446074607790] |