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| n | a(n) |
|---|---|
| 3 | 0 |
| 4 | 0 |
| 5 | 4 |
| 6 | 4 |
| 7 | 7 |
| 8 | 30 |
| 9 | 50 |
| 10 | 105 |
| 11 | 308 |
| 12 | 634 |
| 13 | 1376 |
| 14 | 3553 |
| 15 | 8630 |
| 16 | 20869 |
| 17 | 52340 |
| 18 | 133033 |
| 19 | 342799 |
| 20 | 883814 |
| 21 | 2295764 |
| 22 | 6043202 |
| 23 | 15919001 |
| 24 | 41993543 |
| 25 | 111425390 |
| 26 | 296103536 |
| 27 | 787274963 |
| 28 | 2097945858 |
| 29 | 5598391955 |
| 30 | 14950833524 |
| 31 | 39977574004 |
[0,0,4,4,7,30,50,105,308,634,1376,3553,8630,20869, 52340,133033,342799,883814,2295764,6043202, 15919001,41993543,111425390,296103536,787274963, 2097945858,5598391955,14950833524,39977574004] |