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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 12 |
| 4 | 30 |
| 5 | 77 |
| 6 | 202 |
| 7 | 540 |
| 8 | 1464 |
| 9 | 4014 |
| 10 | 11101 |
| 11 | 30910 |
| 12 | 86542 |
| 13 | 243416 |
| 14 | 687364 |
| 15 | 1947736 |
| 16 | 5536216 |
| 17 | 15779646 |
| 18 | 45088304 |
| 19 | 129124925 |
| 20 | 370550378 |
| 21 | 1065368994 |
| 22 | 3068348448 |
| 23 | 8851297414 |
| 24 | 25571726480 |
| 25 | 73981434516 |
| 26 | 214317561452 |
[1,2,5,12,30,77,202,540,1464,4014,11101,30910, 86542,243416,687364,1947736,5536216,15779646, 45088304,129124925,370550378,1065368994, 3068348448,8851297414,25571726480,73981434516, 214317561452] |