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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 11 |
| 4 | 32 |
| 5 | 110 |
| 6 | 360 |
| 7 | 1195 |
| 8 | 4144 |
| 9 | 14386 |
| 10 | 49928 |
| 11 | 175670 |
| 12 | 625360 |
| 13 | 2217916 |
| 14 | 7928624 |
| 15 | 28528467 |
| 16 | 102759712 |
| 17 | 371080938 |
| 18 | 1345548072 |
| 19 | 4892984610 |
| 20 | 17803931984 |
| 21 | 64981731748 |
| 22 | 237693327312 |
| 23 | 870395679966 |
| 24 | 3192368750176 |
| 25 | 11729242090996 |
| 26 | 43154714474832 |
| 27 | 158912472263628 |
| 28 | 586051248304416 |
| 29 | 2163755202849400 |
[1,1,4,11,32,110,360,1195,4144,14386,49928,175670, 625360,2217916,7928624,28528467,102759712, 371080938,1345548072,4892984610,17803931984, 64981731748,237693327312,870395679966, 3192368750176,11729242090996,43154714474832, 158912472263628,586051248304416,2163755202849400] |