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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 11 |
| 5 | 26 |
| 6 | 65 |
| 7 | 163 |
| 8 | 416 |
| 9 | 1068 |
| 10 | 2756 |
| 11 | 7148 |
| 12 | 18614 |
| 13 | 48639 |
| 14 | 127463 |
| 15 | 334865 |
| 16 | 881658 |
| 17 | 2325751 |
| 18 | 6145597 |
| 19 | 16263866 |
| 20 | 43099804 |
| 21 | 114356611 |
| 22 | 303761260 |
| 23 | 807692035 |
| 24 | 2149632061 |
| 25 | 5726042115 |
| 26 | 15264691107 |
| 27 | 40722913454 |
| 28 | 108713644516 |
| 29 | 290404350963 |
| 30 | 776207020880 |
[1,1,2,5,11,26,65,163,416,1068,2756,7148,18614, 48639,127463,334865,881658,2325751,6145597, 16263866,43099804,114356611,303761260,807692035, 2149632061,5726042115,15264691107,40722913454, 108713644516,290404350963,776207020880] |