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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 12 |
| 3 | 94 |
| 4 | 836 |
| 5 | 8025 |
| 6 | 81136 |
| 7 | 852012 |
| 8 | 9210604 |
| 9 | 101884076 |
| 10 | 1148162064 |
| 11 | 13138949028 |
| 12 | 152296165996 |
| 13 | 1784568913542 |
| 14 | 21106289095896 |
| 15 | 251636459582520 |
| 16 | 3021119305369280 |
| 17 | 36494117062138956 |
| 18 | 443229504130411376 |
| 19 | 5409100104838981832 |
| 20 | 66296660011662002352 |
| 21 | 815719349332409935946 |
[1,2,12,94,836,8025,81136,852012,9210604, 101884076,1148162064,13138949028,152296165996, 1784568913542,21106289095896,251636459582520, 3021119305369280,36494117062138956, 443229504130411376,5409100104838981832, 66296660011662002352,815719349332409935946] |