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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 3 |
| 4 | 21 |
| 5 | 75 |
| 6 | 195 |
| 7 | 420 |
| 8 | 798 |
| 9 | 1386 |
| 10 | 2250 |
| 11 | 3465 |
| 12 | 5115 |
| 13 | 7293 |
| 14 | 10101 |
| 15 | 13650 |
| 16 | 18060 |
| 17 | 23460 |
| 18 | 29988 |
| 19 | 37791 |
| 20 | 47025 |
| 21 | 57855 |
| 22 | 70455 |
| 23 | 85008 |
| 24 | 101706 |
| 25 | 120750 |
| 26 | 142350 |
| 27 | 166725 |
| 28 | 194103 |
| 29 | 224721 |
| 30 | 258825 |
| 31 | 296670 |
| 32 | 338520 |
| 33 | 384648 |
| 34 | 435336 |
| 35 | 490875 |
| 36 | 551565 |
| 37 | 617715 |
| 38 | 689643 |
[0,0,3,21,75,195,420,798,1386,2250,3465,5115,7293, 10101,13650,18060,23460,29988,37791,47025,57855, 70455,85008,101706,120750,142350,166725,194103, 224721,258825,296670,338520,384648,435336,490875, 551565,617715,689643] |