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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 2 |
| 5 | 1 |
| 6 | 2 |
| 7 | 2 |
| 8 | 4 |
| 9 | 7 |
| 10 | 12 |
| 11 | 16 |
| 12 | 26 |
| 13 | 42 |
| 14 | 66 |
| 15 | 104 |
| 16 | 210 |
| 17 | 318 |
| 18 | 620 |
| 19 | 970 |
| 20 | 1748 |
| 21 | 3281 |
| 22 | 5948 |
| 23 | 10480 |
| 24 | 18976 |
| 25 | 34233 |
| 26 | 60836 |
| 27 | 111430 |
| 28 | 209460 |
| 29 | 378529 |
| 30 | 704934 |
| 31 | 1284836 |
| 32 | 2387758 |
| 33 | 4466874 |
| 34 | 8331820 |
| 35 | 15525814 |
| 36 | 28987902 |
| 37 | 54162165 |
| 38 | 101242982 |
| 39 | 190267598 |
| 40 | 358969426 |
| 41 | 674845081 |
[1,1,0,0,2,1,2,2,4,7,12,16,26,42,66,104,210,318, 620,970,1748,3281,5948,10480,18976,34233,60836, 111430,209460,378529,704934,1284836,2387758, 4466874,8331820,15525814,28987902,54162165, 101242982,190267598,358969426,674845081] |