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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 27 |
| 4 | 110 |
| 5 | 472 |
| 6 | 2077 |
| 7 | 9345 |
| 8 | 42672 |
| 9 | 197231 |
| 10 | 920109 |
| 11 | 4325028 |
| 12 | 20456323 |
| 13 | 97251702 |
| 14 | 464357938 |
| 15 | 2225412247 |
| 16 | 10699151819 |
| 17 | 51580477446 |
| 18 | 249269706390 |
| 19 | 1207192943591 |
| 20 | 5857368451966 |
| 21 | 28468107671277 |
| 22 | 138570095211652 |
| 23 | 675414937449190 |
| 24 | 3296144191756004 |
| 25 | 16103773890351584 |
| 26 | 78757640197138906 |
[1,2,7,27,110,472,2077,9345,42672,197231,920109, 4325028,20456323,97251702,464357938,2225412247, 10699151819,51580477446,249269706390, 1207192943591,5857368451966,28468107671277, 138570095211652,675414937449190,3296144191756004, 16103773890351584,78757640197138906] |