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| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 49 |
| 3 | 229 |
| 4 | 971 |
| 5 | 4351 |
| 6 | 20124 |
| 7 | 92597 |
| 8 | 423074 |
| 9 | 1932355 |
| 10 | 8836938 |
| 11 | 40424590 |
| 12 | 184890099 |
| 13 | 845559045 |
| 14 | 3867059514 |
| 15 | 17685848557 |
| 16 | 80885615913 |
| 17 | 369926354240 |
| 18 | 1691838530486 |
| 19 | 7737537171921 |
| 20 | 35387239493020 |
| 21 | 161841764228828 |
| 22 | 740175150497968 |
[7,49,229,971,4351,20124,92597,423074,1932355, 8836938,40424590,184890099,845559045,3867059514, 17685848557,80885615913,369926354240, 1691838530486,7737537171921,35387239493020, 161841764228828,740175150497968] |