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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 22 |
| 4 | 122 |
| 5 | 758 |
| 6 | 5047 |
| 7 | 35208 |
| 8 | 253998 |
| 9 | 1879438 |
| 10 | 14185171 |
| 11 | 108782518 |
| 12 | 845210808 |
| 13 | 6639273704 |
| 14 | 52638802244 |
| 15 | 420681902896 |
| 16 | 3385389615846 |
| 17 | 27409394579262 |
| 18 | 223110429785275 |
| 19 | 1824795182575650 |
| 20 | 14988782110022490 |
| 21 | 123592674062444070 |
| 22 | 1022669887394585295 |
[1,2,5,22,122,758,5047,35208,253998,1879438, 14185171,108782518,845210808,6639273704, 52638802244,420681902896,3385389615846, 27409394579262,223110429785275,1824795182575650, 14988782110022490,123592674062444070, 1022669887394585295] |