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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 81 |
| 7 | 244 |
| 8 | 819 |
| 9 | 2695 |
| 10 | 9463 |
| 11 | 32922 |
| 12 | 120808 |
| 13 | 437836 |
| 14 | 1659640 |
| 15 | 6217694 |
| 16 | 24120576 |
| 17 | 92725987 |
| 18 | 366692792 |
| 19 | 1438275924 |
| 20 | 5781789727 |
| 21 | 23060129968 |
| 22 | 93964095455 |
| 23 | 380158396326 |
| 24 | 1566773918574 |
| 25 | 6416020471974 |
| 26 | 26705782715536 |
| 27 | 110498732504920 |
| 28 | 463940330488819 |
| 29 | 1937038870676946 |
[1,1,2,4,10,26,81,244,819,2695,9463,32922,120808, 437836,1659640,6217694,24120576,92725987, 366692792,1438275924,5781789727,23060129968, 93964095455,380158396326,1566773918574, 6416020471974,26705782715536,110498732504920, 463940330488819,1937038870676946] |