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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 6 |
| 3 | 20 |
| 4 | 70 |
| 5 | 252 |
| 6 | 924 |
| 7 | 3432 |
| 8 | 990 |
| 9 | 14300 |
| 10 | 16588 |
| 11 | 17472 |
| 12 | 39676 |
| 13 | 4760 |
| 14 | 18360 |
| 15 | 46512 |
| 16 | 29070 |
| 17 | 30780 |
| 18 | 87780 |
| 19 | 0 |
| 20 | 191268 |
| 21 | 273240 |
| 22 | 322920 |
| 23 | 140400 |
| 24 | 58500 |
| 25 | 190008 |
| 26 | 350784 |
| 27 | 402752 |
| 28 | 611320 |
| 29 | 81840 |
| 30 | 649264 |
| 31 | 41888 |
| 32 | 164934 |
| 33 | 264180 |
| 34 | 295260 |
| 35 | 1316016 |
| 36 | 694564 |
[2,6,20,70,252,924,3432,990,14300,16588,17472, 39676,4760,18360,46512,29070,30780,87780,0,191268, 273240,322920,140400,58500,190008,350784,402752, 611320,81840,649264,41888,164934,264180,295260, 1316016,694564] |