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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 0 |
| 3 | 12 |
| 4 | 1 |
| 5 | 56 |
| 6 | 3 |
| 7 | 240 |
| 8 | 4 |
| 9 | 993 |
| 10 | 0 |
| 11 | 4041 |
| 12 | 20 |
| 13 | 16257 |
| 14 | 0 |
| 15 | 65343 |
| 16 | 64 |
| 17 | 261651 |
| 18 | 8 |
| 19 | 1047747 |
| 20 | 280 |
| 21 | 4192320 |
| 22 | 25 |
| 23 | 16774112 |
| 24 | 1025 |
| 25 | 67100736 |
| 26 | 161 |
| 27 | 268422656 |
| 28 | 4129 |
| 29 | 1073710976 |
| 30 | 33 |
| 31 | 4294917196 |
| 32 | 16643 |
| 33 | 17179738176 |
| 34 | 2463 |
| 35 | 68719272448 |
| 36 | 65561 |
| 37 | 274877411520 |
| 38 | 1561 |
[1,2,0,12,1,56,3,240,4,993,0,4041,20,16257,0, 65343,64,261651,8,1047747,280,4192320,25,16774112, 1025,67100736,161,268422656,4129,1073710976,33, 4294917196,16643,17179738176,2463,68719272448, 65561,274877411520,1561] |