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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 12 |
| 5 | 62 |
| 6 | 206 |
| 7 | 1189 |
| 8 | 4949 |
| 9 | 31775 |
| 10 | 156972 |
| 11 | 1110280 |
| 12 | 6301550 |
| 13 | 48637701 |
| 14 | 310279615 |
| 15 | 2591820857 |
| 16 | 18293310174 |
| 17 | 164218811718 |
| 18 | 1267153412532 |
| 19 | 12152174863961 |
| 20 | 101557600812015 |
| 21 | 1035203191874931 |
| 22 | 9299499328238110 |
| 23 | 100314319611860936 |
| 24 | 962663031508255416 |
[0,1,1,5,12,62,206,1189,4949,31775,156972,1110280, 6301550,48637701,310279615,2591820857,18293310174, 164218811718,1267153412532,12152174863961, 101557600812015,1035203191874931,9299499328238110, 100314319611860936,962663031508255416] |