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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 15 |
| 3 | 10 |
| 4 | 60 |
| 5 | 260 |
| 6 | 35 |
| 7 | 231 |
| 8 | 1050 |
| 9 | 4375 |
| 10 | 126 |
| 11 | 882 |
| 12 | 4140 |
| 13 | 17640 |
| 14 | 72324 |
| 15 | 462 |
| 16 | 3366 |
| 17 | 16170 |
| 18 | 70070 |
| 19 | 291060 |
| 20 | 1183644 |
| 21 | 1716 |
| 22 | 12870 |
| 23 | 62920 |
| 24 | 276276 |
| 25 | 1159704 |
| 26 | 4756752 |
| 27 | 19253520 |
| 28 | 6435 |
| 29 | 49335 |
| 30 | 244530 |
| 31 | 1085175 |
| 32 | 4594590 |
| 33 | 18981270 |
| 34 | 77297220 |
| 35 | 311949495 |
| 36 | 24310 |
| 37 | 189618 |
| 38 | 950300 |
[1,3,15,10,60,260,35,231,1050,4375,126,882,4140, 17640,72324,462,3366,16170,70070,291060,1183644, 1716,12870,62920,276276,1159704,4756752,19253520, 6435,49335,244530,1085175,4594590,18981270, 77297220,311949495,24310,189618,950300] |