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| n | a(n) |
|---|---|
| 1 | 138 |
| 2 | 3186 |
| 3 | 32060 |
| 4 | 199735 |
| 5 | 909900 |
| 6 | 3323712 |
| 7 | 10301232 |
| 8 | 28115505 |
| 9 | 69342790 |
| 10 | 157454154 |
| 11 | 333771516 |
| 12 | 667605263 |
| 13 | 1270560760 |
| 14 | 2316187440 |
| 15 | 4066346688 |
| 16 | 6905893425 |
| 17 | 11387501154 |
| 18 | 18288711250 |
| 19 | 28683554460 |
| 20 | 44031375927 |
| 21 | 66285794564 |
[138,3186,32060,199735,909900,3323712,10301232, 28115505,69342790,157454154,333771516,667605263, 1270560760,2316187440,4066346688,6905893425, 11387501154,18288711250,28683554460,44031375927, 66285794564] |