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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 23 |
| 7 | 58 |
| 8 | 156 |
| 9 | 426 |
| 10 | 1194 |
| 11 | 3393 |
| 12 | 9802 |
| 13 | 28601 |
| 14 | 84347 |
| 15 | 250732 |
| 16 | 750908 |
| 17 | 2262817 |
| 18 | 6857386 |
| 19 | 20882889 |
| 20 | 63877262 |
| 21 | 196162762 |
| 22 | 604567254 |
| 23 | 1869318719 |
| 24 | 5797113028 |
| 25 | 18026873112 |
| 26 | 56197262814 |
| 27 | 175594836698 |
| 28 | 549839459963 |
| 29 | 1725126992844 |
| 30 | 5422602630117 |
| 31 | 17074281639963 |
| 32 | 53848886560675 |
| 33 | 170085320026578 |
[0,1,1,2,4,9,23,58,156,426,1194,3393,9802,28601, 84347,250732,750908,2262817,6857386,20882889, 63877262,196162762,604567254,1869318719, 5797113028,18026873112,56197262814,175594836698, 549839459963,1725126992844,5422602630117, 17074281639963,53848886560675,170085320026578] |