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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 26 |
| 4 | 106 |
| 5 | 350 |
| 6 | 1512 |
| 7 | 5110 |
| 8 | 21476 |
| 9 | 77886 |
| 10 | 319148 |
| 11 | 1141038 |
| 12 | 4910266 |
| 13 | 17499058 |
| 14 | 72541048 |
| 15 | 272237050 |
| 16 | 1121013506 |
| 17 | 4112829790 |
| 18 | 17377874692 |
| 19 | 63697436318 |
| 20 | 265450712278 |
| 21 | 1003409368250 |
| 22 | 4102752994248 |
| 23 | 15321419162722 |
| 24 | 64725434306768 |
[1,2,8,26,106,350,1512,5110,21476,77886,319148, 1141038,4910266,17499058,72541048,272237050, 1121013506,4112829790,17377874692,63697436318, 265450712278,1003409368250,4102752994248, 15321419162722,64725434306768] |