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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 6 |
| 3 | 15 |
| 4 | 231 |
| 5 | 276 |
| 6 | 780 |
| 7 | 861 |
| 8 | 1653 |
| 9 | 1770 |
| 10 | 2850 |
| 11 | 3003 |
| 12 | 4371 |
| 13 | 4560 |
| 14 | 5995 |
| 15 | 6216 |
| 16 | 6441 |
| 17 | 11175 |
| 18 | 14028 |
| 19 | 17205 |
| 20 | 17578 |
| 21 | 20301 |
| 22 | 20706 |
| 23 | 24090 |
| 24 | 24531 |
| 25 | 24976 |
| 26 | 28203 |
| 27 | 32640 |
| 28 | 33153 |
| 29 | 36856 |
| 30 | 37401 |
| 31 | 43071 |
| 32 | 47278 |
| 33 | 52975 |
| 34 | 54946 |
| 35 | 56953 |
| 36 | 67528 |
| 37 | 69751 |
| 38 | 76636 |
[0,1,6,15,231,276,780,861,1653,1770,2850,3003, 4371,4560,5995,6216,6441,11175,14028,17205,17578, 20301,20706,24090,24531,24976,28203,32640,33153, 36856,37401,43071,47278,52975,54946,56953,67528, 69751,76636] |