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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 252 |
| 3 | 1925 |
| 4 | 6534 |
| 5 | 20502 |
| 6 | 57710 |
| 7 | 142312 |
| 8 | 308254 |
| 9 | 606051 |
| 10 | 1105332 |
| 11 | 1897899 |
| 12 | 3100250 |
| 13 | 4857000 |
| 14 | 7344010 |
| 15 | 10771530 |
| 16 | 15387310 |
| 17 | 21479725 |
| 18 | 29380900 |
| 19 | 39469835 |
| 20 | 52175530 |
| 21 | 67980110 |
| 22 | 87421950 |
| 23 | 111098800 |
| 24 | 139670910 |
| 25 | 173864155 |
[1,252,1925,6534,20502,57710,142312,308254,606051, 1105332,1897899,3100250,4857000,7344010,10771530, 15387310,21479725,29380900,39469835,52175530, 67980110,87421950,111098800,139670910,173864155] |