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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 27 |
| 5 | 88 |
| 6 | 330 |
| 7 | 1233 |
| 8 | 4757 |
| 9 | 19087 |
| 10 | 77084 |
| 11 | 318057 |
| 12 | 1332943 |
| 13 | 5633800 |
| 14 | 24135510 |
| 15 | 104270601 |
| 16 | 453822577 |
| 17 | 1992313735 |
| 18 | 8796237670 |
| 19 | 39076873799 |
| 20 | 174584332753 |
| 21 | 783445597358 |
| 22 | 3532945065726 |
| 23 | 15995372227192 |
| 24 | 72689772282113 |
| 25 | 331560783129859 |
| 26 | 1517023330197527 |
| 27 | 6962862373775283 |
| 28 | 32048845700046927 |
[1,1,3,8,27,88,330,1233,4757,19087,77084,318057, 1332943,5633800,24135510,104270601,453822577, 1992313735,8796237670,39076873799,174584332753, 783445597358,3532945065726,15995372227192, 72689772282113,331560783129859,1517023330197527, 6962862373775283,32048845700046927] |