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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 23 |
| 2 | 506 |
| 3 | 11132 |
| 4 | 244904 |
| 5 | 5387888 |
| 6 | 118533536 |
| 7 | 2607737792 |
| 8 | 57370231424 |
| 9 | 1262145091075 |
| 10 | 27767191998084 |
| 11 | 610878223835649 |
| 12 | 13439320921695900 |
| 13 | 295665060218165484 |
| 14 | 6504631323498465696 |
| 15 | 143101889088340396368 |
[1,23,506,11132,244904,5387888,118533536, 2607737792,57370231424,1262145091075, 27767191998084,610878223835649,13439320921695900, 295665060218165484,6504631323498465696, 143101889088340396368] |