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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 69 |
| 6 | 198 |
| 7 | 498 |
| 8 | 1121 |
| 9 | 2305 |
| 10 | 4402 |
| 11 | 7910 |
| 12 | 13509 |
| 13 | 22101 |
| 14 | 34854 |
| 15 | 53250 |
| 16 | 79137 |
| 17 | 114785 |
| 18 | 162946 |
| 19 | 226918 |
| 20 | 310613 |
| 21 | 418629 |
| 22 | 556326 |
| 23 | 729906 |
| 24 | 946497 |
| 25 | 1214241 |
| 26 | 1542386 |
| 27 | 1941382 |
| 28 | 2422981 |
| 29 | 3000341 |
| 30 | 3688134 |
[1,2,6,21,69,198,498,1121,2305,4402,7910,13509, 22101,34854,53250,79137,114785,162946,226918, 310613,418629,556326,729906,946497,1214241, 1542386,1941382,2422981,3000341,3688134] |