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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 14 |
| 3 | 55 |
| 4 | 205 |
| 5 | 777 |
| 6 | 2937 |
| 7 | 11118 |
| 8 | 42072 |
| 9 | 159220 |
| 10 | 602554 |
| 11 | 2280320 |
| 12 | 8629690 |
| 13 | 32658395 |
| 14 | 123593159 |
| 15 | 467728718 |
| 16 | 1770083028 |
| 17 | 6698741833 |
| 18 | 25350868523 |
| 19 | 95938394252 |
| 20 | 363071406534 |
| 21 | 1374015557281 |
| 22 | 5199855228676 |
| 23 | 19678448512407 |
[4,14,55,205,777,2937,11118,42072,159220,602554, 2280320,8629690,32658395,123593159,467728718, 1770083028,6698741833,25350868523,95938394252, 363071406534,1374015557281,5199855228676, 19678448512407] |