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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 6 |
| 6 | 9 |
| 7 | 18 |
| 8 | 30 |
| 9 | 56 |
| 10 | 99 |
| 11 | 186 |
| 12 | 335 |
| 13 | 630 |
| 14 | 1161 |
| 15 | 2182 |
| 16 | 4080 |
| 17 | 7710 |
| 18 | 14532 |
| 19 | 27594 |
| 20 | 52377 |
| 21 | 99858 |
| 22 | 190557 |
| 23 | 364722 |
| 24 | 698870 |
| 25 | 1342176 |
| 26 | 2580795 |
| 27 | 4971008 |
| 28 | 9586395 |
| 29 | 18512790 |
| 30 | 35790267 |
| 31 | 69273666 |
| 32 | 134215680 |
| 33 | 260300986 |
| 34 | 505286415 |
| 35 | 981706806 |
| 36 | 1908866960 |
| 37 | 3714566310 |
| 38 | 7233615333 |
| 39 | 14096302710 |
| 40 | 27487764474 |
[1,2,1,2,3,6,9,18,30,56,99,186,335,630,1161,2182, 4080,7710,14532,27594,52377,99858,190557,364722, 698870,1342176,2580795,4971008,9586395,18512790, 35790267,69273666,134215680,260300986,505286415, 981706806,1908866960,3714566310,7233615333, 14096302710,27487764474] |