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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 12 |
| 4 | 37 |
| 5 | 121 |
| 6 | 419 |
| 7 | 1510 |
| 8 | 5604 |
| 9 | 21261 |
| 10 | 82110 |
| 11 | 321662 |
| 12 | 1275077 |
| 13 | 5104886 |
| 14 | 20611814 |
| 15 | 83834609 |
| 16 | 343164051 |
| 17 | 1412600336 |
| 18 | 5843868040 |
| 19 | 24283650452 |
| 20 | 101312783192 |
| 21 | 424212909937 |
| 22 | 1782086178267 |
| 23 | 7508852850710 |
| 24 | 31725558330499 |
| 25 | 134381573170076 |
| 26 | 570532128884181 |
[1,2,5,12,37,121,419,1510,5604,21261,82110,321662, 1275077,5104886,20611814,83834609,343164051, 1412600336,5843868040,24283650452,101312783192, 424212909937,1782086178267,7508852850710, 31725558330499,134381573170076,570532128884181] |