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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 9 |
| 6 | 58 |
| 7 | 341 |
| 8 | 1983 |
| 9 | 11776 |
| 10 | 72345 |
| 11 | 462173 |
| 12 | 3075894 |
| 13 | 21330762 |
| 14 | 154050330 |
| 15 | 1157493707 |
| 16 | 9037925277 |
| 17 | 73244123107 |
| 18 | 615295131046 |
| 19 | 5351329029624 |
| 20 | 48126530239366 |
| 21 | 447043890866154 |
| 22 | 4284293705043796 |
| 23 | 42317095568379559 |
| 24 | 430355360965092107 |
| 25 | 4501973706497500364 |
[0,0,0,0,1,9,58,341,1983,11776,72345,462173, 3075894,21330762,154050330,1157493707,9037925277, 73244123107,615295131046,5351329029624, 48126530239366,447043890866154,4284293705043796, 42317095568379559,430355360965092107, 4501973706497500364] |