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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 3 |
| 4 | 20 |
| 5 | 23 |
| 6 | 88 |
| 7 | 111 |
| 8 | 496 |
| 9 | 415 |
| 10 | 1952 |
| 11 | 1215 |
| 12 | 7360 |
| 13 | 1407 |
| 14 | 28544 |
| 15 | 25855 |
| 16 | 79104 |
| 17 | 32255 |
| 18 | 415232 |
| 19 | 482303 |
| 20 | 1797120 |
| 21 | 1030143 |
| 22 | 5634048 |
| 23 | 5656575 |
| 24 | 22204416 |
| 25 | 30892031 |
| 26 | 116613120 |
| 27 | 53854207 |
| 28 | 400539648 |
| 29 | 274890751 |
| 30 | 1593212928 |
| 31 | 2117795839 |
| 32 | 6804930560 |
| 33 | 3207462911 |
[1,1,6,3,20,23,88,111,496,415,1952,1215,7360,1407, 28544,25855,79104,32255,415232,482303,1797120, 1030143,5634048,5656575,22204416,30892031, 116613120,53854207,400539648,274890751,1593212928, 2117795839,6804930560,3207462911] |