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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 5 |
| 4 | 35 |
| 5 | 11 |
| 6 | 128 |
| 7 | 405 |
| 8 | 1628 |
| 9 | 5153 |
| 10 | 6281 |
| 11 | 20331 |
| 12 | 404505 |
| 13 | 1326005 |
| 14 | 2437316 |
| 15 | 12392316 |
| 16 | 42485480 |
| 17 | 37150046 |
| 18 | 18810 |
| 19 | 179470703 |
| 20 | 2237948990 |
| 21 | 10876002500 |
| 22 | 22548781025 |
| 23 | 26940078203 |
| 24 | 242416922750 |
| 25 | 572687476751 |
| 26 | 4117080477500 |
[0,0,5,35,11,128,405,1628,5153,6281,20331,404505, 1326005,2437316,12392316,42485480,37150046,18810, 179470703,2237948990,10876002500,22548781025, 26940078203,242416922750,572687476751, 4117080477500] |