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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 19 |
| 4 | 69 |
| 5 | 277 |
| 6 | 1185 |
| 7 | 5009 |
| 8 | 21325 |
| 9 | 92733 |
| 10 | 408629 |
| 11 | 1807995 |
| 12 | 8038887 |
| 13 | 35981881 |
| 14 | 162014757 |
| 15 | 732494001 |
| 16 | 3321753179 |
| 17 | 15111904573 |
| 18 | 68984336243 |
| 19 | 315806352009 |
| 20 | 1448850054545 |
| 21 | 6660481232055 |
| 22 | 30684420675499 |
| 23 | 141639855244171 |
| 24 | 654874542763787 |
| 25 | 3032247286729153 |
| 26 | 14060715339443201 |
| 27 | 65292539049162537 |
[1,1,5,19,69,277,1185,5009,21325,92733,408629, 1807995,8038887,35981881,162014757,732494001, 3321753179,15111904573,68984336243,315806352009, 1448850054545,6660481232055,30684420675499, 141639855244171,654874542763787,3032247286729153, 14060715339443201,65292539049162537] |