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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 10 |
| 3 | 40 |
| 4 | 176 |
| 5 | 808 |
| 6 | 3720 |
| 7 | 17152 |
| 8 | 81440 |
| 9 | 384448 |
| 10 | 1824448 |
| 11 | 8758400 |
| 12 | 42003840 |
| 13 | 201892480 |
| 14 | 977114240 |
| 15 | 4726665216 |
| 16 | 22901914112 |
| 17 | 111430159360 |
| 18 | 542141168640 |
| 19 | 2640679776256 |
| 20 | 12898118598656 |
| 21 | 63006347137024 |
| 22 | 308047467597824 |
| 23 | 1509004351340544 |
| 24 | 7393407993561088 |
| 25 | 36248756250542080 |
| 26 | 177971449582911488 |
[1,2,10,40,176,808,3720,17152,81440,384448, 1824448,8758400,42003840,201892480,977114240, 4726665216,22901914112,111430159360,542141168640, 2640679776256,12898118598656,63006347137024, 308047467597824,1509004351340544,7393407993561088, 36248756250542080,177971449582911488] |