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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 45 |
| 3 | 203 |
| 4 | 1401 |
| 5 | 8493 |
| 6 | 53575 |
| 7 | 331044 |
| 8 | 2075845 |
| 9 | 12918219 |
| 10 | 80580322 |
| 11 | 502619295 |
| 12 | 3134437862 |
| 13 | 19546771248 |
| 14 | 121911745097 |
| 15 | 760295303506 |
| 16 | 4741622947607 |
| 17 | 29571672780560 |
| 18 | 184425813286537 |
| 19 | 1150185892959279 |
| 20 | 7173237104348896 |
[2,45,203,1401,8493,53575,331044,2075845,12918219, 80580322,502619295,3134437862,19546771248, 121911745097,760295303506,4741622947607, 29571672780560,184425813286537,1150185892959279, 7173237104348896] |