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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 21 |
| 5 | 60 |
| 6 | 160 |
| 7 | 429 |
| 8 | 1134 |
| 9 | 2992 |
| 10 | 7865 |
| 11 | 20648 |
| 12 | 54144 |
| 13 | 141897 |
| 14 | 371722 |
| 15 | 973560 |
| 16 | 2549421 |
| 17 | 6675460 |
| 18 | 17478176 |
| 19 | 45761045 |
| 20 | 119808150 |
| 21 | 313668576 |
| 22 | 821205937 |
| 23 | 2149962768 |
| 24 | 5628704256 |
| 25 | 14736185425 |
| 26 | 38579909330 |
| 27 | 101003635304 |
[1,2,8,21,60,160,429,1134,2992,7865,20648,54144, 141897,371722,973560,2549421,6675460,17478176, 45761045,119808150,313668576,821205937,2149962768, 5628704256,14736185425,38579909330,101003635304] |