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| n | a(n) |
|---|---|
| 1 | 74 |
| 2 | 284 |
| 3 | 1074 |
| 4 | 4256 |
| 5 | 16986 |
| 6 | 68692 |
| 7 | 279504 |
| 8 | 1143842 |
| 9 | 4699050 |
| 10 | 19364230 |
| 11 | 79981548 |
| 12 | 330948764 |
| 13 | 1371291912 |
| 14 | 5688057508 |
| 15 | 23613366558 |
| 16 | 98091679448 |
| 17 | 407685449946 |
| 18 | 1695079113772 |
| 19 | 7050018583818 |
| 20 | 29329074681854 |
| 21 | 122037419381370 |
[74,284,1074,4256,16986,68692,279504,1143842, 4699050,19364230,79981548,330948764,1371291912, 5688057508,23613366558,98091679448,407685449946, 1695079113772,7050018583818,29329074681854, 122037419381370] |