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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 0 |
| 6 | 5 |
| 7 | 11 |
| 8 | 6 |
| 9 | 35 |
| 10 | 120 |
| 11 | 136 |
| 12 | 336 |
| 13 | 1330 |
| 14 | 2310 |
| 15 | 4301 |
| 16 | 15456 |
| 17 | 35100 |
| 18 | 64701 |
| 19 | 193662 |
| 20 | 508921 |
| 21 | 1023000 |
| 22 | 2643432 |
| 23 | 7298984 |
| 24 | 16196682 |
| 25 | 38795055 |
| 26 | 105939288 |
| 27 | 254015541 |
| 28 | 596987183 |
| 29 | 1575487320 |
| 30 | 3959803694 |
| 31 | 9418896773 |
| 32 | 24081344034 |
| 33 | 61781452530 |
| 34 | 150293865540 |
[1,0,0,1,1,0,5,11,6,35,120,136,336,1330,2310,4301, 15456,35100,64701,193662,508921,1023000,2643432, 7298984,16196682,38795055,105939288,254015541, 596987183,1575487320,3959803694,9418896773, 24081344034,61781452530,150293865540] |