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| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 49 |
| 3 | 336 |
| 4 | 2298 |
| 5 | 15630 |
| 6 | 105892 |
| 7 | 714874 |
| 8 | 4811578 |
| 9 | 32300252 |
| 10 | 216337084 |
| 11 | 1446056046 |
| 12 | 9648789758 |
| 13 | 64281141440 |
| 14 | 427655897226 |
| 15 | 2841661493142 |
| 16 | 18861464959350 |
| 17 | 125070420653458 |
| 18 | 828618463551536 |
| 19 | 5485481885293294 |
| 20 | 36288577806336542 |
[7,49,336,2298,15630,105892,714874,4811578, 32300252,216337084,1446056046,9648789758, 64281141440,427655897226,2841661493142, 18861464959350,125070420653458,828618463551536, 5485481885293294,36288577806336542] |