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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 6 |
| 4 | 20 |
| 5 | 50 |
| 6 | 105 |
| 7 | 196 |
| 8 | 336 |
| 9 | 540 |
| 10 | 825 |
| 11 | 1210 |
| 12 | 1716 |
| 13 | 2366 |
| 14 | 3185 |
| 15 | 4200 |
| 16 | 5440 |
| 17 | 6936 |
| 18 | 8721 |
| 19 | 10830 |
| 20 | 13300 |
| 21 | 16170 |
| 22 | 19481 |
| 23 | 23276 |
| 24 | 27600 |
| 25 | 32500 |
| 26 | 38025 |
| 27 | 44226 |
| 28 | 51156 |
| 29 | 58870 |
| 30 | 67425 |
| 31 | 76880 |
| 32 | 87296 |
| 33 | 98736 |
| 34 | 111265 |
| 35 | 124950 |
| 36 | 139860 |
| 37 | 156066 |
| 38 | 173641 |
| 39 | 192660 |
| 40 | 213200 |
| 41 | 235340 |
[0,0,1,6,20,50,105,196,336,540,825,1210,1716,2366, 3185,4200,5440,6936,8721,10830,13300,16170,19481, 23276,27600,32500,38025,44226,51156,58870,67425, 76880,87296,98736,111265,124950,139860,156066, 173641,192660,213200,235340] |