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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 16 |
| 3 | 119 |
| 4 | 948 |
| 5 | 7732 |
| 6 | 64231 |
| 7 | 540311 |
| 8 | 4588076 |
| 9 | 39244106 |
| 10 | 337624066 |
| 11 | 2918384229 |
| 12 | 25325306031 |
| 13 | 220497804256 |
| 14 | 1925231880973 |
| 15 | 16850975055139 |
| 16 | 147807248526268 |
| 17 | 1298926641563548 |
| 18 | 11434042768577866 |
| 19 | 100800817171002817 |
| 20 | 889839745865544598 |
[1,2,16,119,948,7732,64231,540311,4588076, 39244106,337624066,2918384229,25325306031, 220497804256,1925231880973,16850975055139, 147807248526268,1298926641563548, 11434042768577866,100800817171002817, 889839745865544598] |