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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 10 |
| 4 | 35 |
| 5 | 117 |
| 6 | 429 |
| 7 | 1563 |
| 8 | 6023 |
| 9 | 23289 |
| 10 | 92152 |
| 11 | 369488 |
| 12 | 1502119 |
| 13 | 6160145 |
| 14 | 25528852 |
| 15 | 106682938 |
| 16 | 448960587 |
| 17 | 1901408027 |
| 18 | 8104762740 |
| 19 | 34722538926 |
| 20 | 149465829383 |
| 21 | 646360473228 |
| 22 | 2806706370121 |
| 23 | 12231645222422 |
| 24 | 53492893993153 |
| 25 | 234717283187637 |
| 26 | 1032901850100970 |
| 27 | 4557956790155818 |
| 28 | 20167098103048672 |
[1,1,4,10,35,117,429,1563,6023,23289,92152,369488, 1502119,6160145,25528852,106682938,448960587, 1901408027,8104762740,34722538926,149465829383, 646360473228,2806706370121,12231645222422, 53492893993153,234717283187637,1032901850100970, 4557956790155818,20167098103048672] |