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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 23 |
| 4 | 40 |
| 5 | 273 |
| 6 | 1870 |
| 7 | 7343 |
| 8 | 12816 |
| 9 | 87841 |
| 10 | 602070 |
| 11 | 2364359 |
| 12 | 4126648 |
| 13 | 28284465 |
| 14 | 193864606 |
| 15 | 761316191 |
| 16 | 1328767776 |
| 17 | 9107509825 |
| 18 | 62423800998 |
| 19 | 245141449079 |
| 20 | 427859097160 |
| 21 | 2932589879121 |
| 22 | 20100270056686 |
| 23 | 78934785287183 |
[1,6,23,40,273,1870,7343,12816,87841,602070, 2364359,4126648,28284465,193864606,761316191, 1328767776,9107509825,62423800998,245141449079, 427859097160,2932589879121,20100270056686, 78934785287183] |