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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 1 |
| 5 | 4 |
| 6 | 10 |
| 7 | 60 |
| 8 | 1 |
| 9 | 5 |
| 10 | 15 |
| 11 | 140 |
| 12 | 280 |
| 13 | 1260 |
| 14 | 12600 |
| 15 | 1 |
| 16 | 6 |
| 17 | 21 |
| 18 | 224 |
| 19 | 630 |
| 20 | 3780 |
| 21 | 34650 |
| 22 | 110880 |
| 23 | 360360 |
| 24 | 2522520 |
| 25 | 37837800 |
| 26 | 1 |
| 27 | 7 |
| 28 | 28 |
| 29 | 336 |
| 30 | 1050 |
| 31 | 7392 |
| 32 | 74844 |
| 33 | 276276 |
| 34 | 1513512 |
| 35 | 9459450 |
| 36 | 131171040 |
| 37 | 428828400 |
| 38 | 2058376320 |
| 39 | 9777287520 |
| 40 | 97772875200 |
| 41 | 2053230379200 |
[1,1,1,3,1,4,10,60,1,5,15,140,280,1260,12600,1,6, 21,224,630,3780,34650,110880,360360,2522520, 37837800,1,7,28,336,1050,7392,74844,276276, 1513512,9459450,131171040,428828400,2058376320, 9777287520,97772875200,2053230379200] |