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| n | a(n) |
|---|---|
| 1 | 50 |
| 2 | 228 |
| 3 | 928 |
| 4 | 3574 |
| 5 | 13346 |
| 6 | 48848 |
| 7 | 176420 |
| 8 | 631130 |
| 9 | 2242678 |
| 10 | 7930164 |
| 11 | 27941848 |
| 12 | 98196574 |
| 13 | 344438730 |
| 14 | 1206482520 |
| 15 | 4221685708 |
| 16 | 14761290914 |
| 17 | 51584989022 |
| 18 | 180196526268 |
| 19 | 629274809856 |
| 20 | 2197047322662 |
| 21 | 7669531252530 |
| 22 | 26769919917152 |
[50,228,928,3574,13346,48848,176420,631130, 2242678,7930164,27941848,98196574,344438730, 1206482520,4221685708,14761290914,51584989022, 180196526268,629274809856,2197047322662, 7669531252530,26769919917152] |