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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 7 |
| 6 | 17 |
| 7 | 39 |
| 8 | 102 |
| 9 | 258 |
| 10 | 651 |
| 11 | 1620 |
| 12 | 4028 |
| 13 | 9956 |
| 14 | 24588 |
| 15 | 60742 |
| 16 | 150108 |
| 17 | 371689 |
| 18 | 921822 |
| 19 | 2291257 |
| 20 | 5706077 |
| 21 | 14240518 |
| 22 | 35607189 |
| 23 | 89202758 |
| 24 | 223857382 |
| 25 | 562716179 |
| 26 | 1416686294 |
| 27 | 3571809027 |
| 28 | 9017514253 |
| 29 | 22794726763 |
[1,2,2,3,4,7,17,39,102,258,651,1620,4028,9956, 24588,60742,150108,371689,921822,2291257,5706077, 14240518,35607189,89202758,223857382,562716179, 1416686294,3571809027,9017514253,22794726763] |