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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 15 |
| 3 | 90 |
| 4 | 310 |
| 5 | 990 |
| 6 | 2220 |
| 7 | 5300 |
| 8 | 9660 |
| 9 | 17130 |
| 10 | 28670 |
| 11 | 52848 |
| 12 | 75696 |
| 13 | 128541 |
| 14 | 183393 |
| 15 | 257628 |
| 16 | 344316 |
| 17 | 529038 |
| 18 | 683316 |
| 19 | 1001110 |
| 20 | 1256010 |
| 21 | 1607004 |
| 22 | 2049490 |
| 23 | 2837700 |
| 24 | 3330636 |
| 25 | 4177186 |
| 26 | 5150340 |
| 27 | 6273810 |
| 28 | 7432702 |
| 29 | 9779991 |
| 30 | 11124711 |
| 31 | 14381168 |
| 32 | 16610640 |
| 33 | 19542393 |
| 34 | 23032799 |
| 35 | 26873769 |
[1,15,90,310,990,2220,5300,9660,17130,28670,52848, 75696,128541,183393,257628,344316,529038,683316, 1001110,1256010,1607004,2049490,2837700,3330636, 4177186,5150340,6273810,7432702,9779991,11124711, 14381168,16610640,19542393,23032799,26873769] |