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| n | a(n) |
|---|---|
| 4 | 1 |
| 5 | 2 |
| 6 | 8 |
| 7 | 25 |
| 8 | 86 |
| 9 | 272 |
| 10 | 875 |
| 11 | 2732 |
| 12 | 8505 |
| 13 | 26104 |
| 14 | 79708 |
| 15 | 241522 |
| 16 | 728632 |
| 17 | 2187951 |
| 18 | 6548819 |
| 19 | 19542662 |
| 20 | 58184124 |
| 21 | 172880565 |
| 22 | 512837063 |
| 23 | 1519158462 |
| 24 | 4494920802 |
| 25 | 13286473612 |
| 26 | 39240530012 |
| 27 | 115811180864 |
| 28 | 341588823740 |
| 29 | 1007007175952 |
| 30 | 2967361180383 |
[1,2,8,25,86,272,875,2732,8505,26104,79708,241522, 728632,2187951,6548819,19542662,58184124, 172880565,512837063,1519158462,4494920802, 13286473612,39240530012,115811180864,341588823740, 1007007175952,2967361180383] |