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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 19 |
| 3 | 135 |
| 4 | 605 |
| 5 | 2054 |
| 6 | 5778 |
| 7 | 14178 |
| 8 | 31350 |
| 9 | 63855 |
| 10 | 121693 |
| 11 | 219505 |
| 12 | 378027 |
| 13 | 625820 |
| 14 | 1001300 |
| 15 | 1555092 |
| 16 | 2352732 |
| 17 | 3477741 |
| 18 | 5035095 |
| 19 | 7155115 |
| 20 | 9997801 |
| 21 | 13757634 |
| 22 | 18668870 |
| 23 | 25011350 |
| 24 | 33116850 |
| 25 | 43375995 |
| 26 | 56245761 |
| 27 | 72257589 |
| 28 | 92026135 |
[1,19,135,605,2054,5778,14178,31350,63855,121693, 219505,378027,625820,1001300,1555092,2352732, 3477741,5035095,7155115,9997801,13757634,18668870, 25011350,33116850,43375995,56245761,72257589, 92026135] |