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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 10 |
| 3 | 36 |
| 4 | 130 |
| 5 | 476 |
| 6 | 1769 |
| 7 | 6630 |
| 8 | 25017 |
| 9 | 94961 |
| 10 | 362181 |
| 11 | 1386826 |
| 12 | 5328341 |
| 13 | 20531796 |
| 14 | 79315343 |
| 15 | 307077270 |
| 16 | 1191203283 |
| 17 | 4628896233 |
| 18 | 18015359847 |
| 19 | 70212552034 |
| 20 | 273990076816 |
| 21 | 1070416998344 |
| 22 | 4186254302972 |
| 23 | 16387566482916 |
[1,3,10,36,130,476,1769,6630,25017,94961,362181, 1386826,5328341,20531796,79315343,307077270, 1191203283,4628896233,18015359847,70212552034, 273990076816,1070416998344,4186254302972, 16387566482916] |