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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 14 |
| 6 | 43 |
| 7 | 126 |
| 8 | 396 |
| 9 | 1230 |
| 10 | 3970 |
| 11 | 12830 |
| 12 | 42478 |
| 13 | 140982 |
| 14 | 475671 |
| 15 | 1608542 |
| 16 | 5508488 |
| 17 | 18900350 |
| 18 | 65498136 |
| 19 | 227340182 |
| 20 | 795468118 |
| 21 | 2787057078 |
| 22 | 9830186006 |
| 23 | 34711199838 |
| 24 | 123255087526 |
| 25 | 438093298054 |
| 26 | 1564557142054 |
| 27 | 5592309891438 |
| 28 | 20070764026326 |
| 29 | 72089179111398 |
| 30 | 259844964879959 |
| 31 | 937255549483022 |
| 32 | 3391151925316544 |
[1,0,1,2,6,14,43,126,396,1230,3970,12830,42478, 140982,475671,1608542,5508488,18900350,65498136, 227340182,795468118,2787057078,9830186006, 34711199838,123255087526,438093298054, 1564557142054,5592309891438,20070764026326, 72089179111398,259844964879959,937255549483022, 3391151925316544] |