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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 15 |
| 7 | 27 |
| 8 | 41 |
| 9 | 68 |
| 10 | 111 |
| 11 | 218 |
| 12 | 328 |
| 13 | 624 |
| 14 | 929 |
| 15 | 1518 |
| 16 | 2016 |
| 17 | 3689 |
| 18 | 4965 |
| 19 | 9252 |
| 20 | 13177 |
| 21 | 20016 |
| 22 | 30697 |
| 23 | 56749 |
| 24 | 69434 |
| 25 | 94242 |
| 26 | 149558 |
| 27 | 190292 |
| 28 | 258370 |
| 29 | 492924 |
| 30 | 615063 |
| 31 | 1149403 |
| 32 | 1325124 |
| 33 | 1841343 |
| 34 | 2737190 |
| 35 | 3592273 |
| 36 | 4193855 |
| 37 | 8216492 |
| 38 | 12668800 |
| 39 | 17654339 |
| 40 | 20368544 |
[0,0,1,2,4,9,15,27,41,68,111,218,328,624,929,1518, 2016,3689,4965,9252,13177,20016,30697,56749,69434, 94242,149558,190292,258370,492924,615063,1149403, 1325124,1841343,2737190,3592273,4193855,8216492, 12668800,17654339,20368544] |