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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 5 |
| 4 | 14 |
| 5 | 50 |
| 6 | 194 |
| 7 | 723 |
| 8 | 2659 |
| 9 | 9884 |
| 10 | 36780 |
| 11 | 136636 |
| 12 | 507517 |
| 13 | 1885793 |
| 14 | 7006962 |
| 15 | 26034006 |
| 16 | 96728470 |
| 17 | 359395319 |
| 18 | 1335332919 |
| 19 | 4961420008 |
| 20 | 18434129192 |
| 21 | 68491926888 |
| 22 | 254481427113 |
| 23 | 945524491213 |
| 24 | 3513091674982 |
| 25 | 13052875206698 |
[0,0,1,5,14,50,194,723,2659,9884,36780,136636, 507517,1885793,7006962,26034006,96728470, 359395319,1335332919,4961420008,18434129192, 68491926888,254481427113,945524491213, 3513091674982,13052875206698] |