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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 12 |
| 5 | 100 |
| 6 | 1070 |
| 7 | 14116 |
| 8 | 222614 |
| 9 | 4092964 |
| 10 | 86058372 |
| 11 | 2038072080 |
| 12 | 53704876742 |
| 13 | 1558947707912 |
| 14 | 49437387429404 |
| 15 | 1700708685654304 |
| 16 | 63087246457132054 |
| 17 | 2510333378920658240 |
| 18 | 106666494341060615560 |
| 19 | 4820550659164606795712 |
[1,1,2,12,100,1070,14116,222614,4092964,86058372, 2038072080,53704876742,1558947707912, 49437387429404,1700708685654304,63087246457132054, 2510333378920658240,106666494341060615560, 4820550659164606795712] |