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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 1 |
| 5 | 5 |
| 6 | 9 |
| 7 | 15 |
| 8 | 30 |
| 9 | 65 |
| 10 | 138 |
| 11 | 274 |
| 12 | 563 |
| 13 | 1149 |
| 14 | 2441 |
| 15 | 5110 |
| 16 | 9090 |
| 17 | 19645 |
| 18 | 37524 |
| 19 | 79178 |
| 20 | 156697 |
| 21 | 324182 |
| 22 | 663749 |
| 23 | 1353984 |
| 24 | 2529510 |
| 25 | 5088926 |
| 26 | 10686159 |
| 27 | 19987129 |
| 28 | 40800192 |
| 29 | 85303150 |
| 30 | 162549135 |
| 31 | 341440697 |
| 32 | 630392773 |
| 33 | 1317158898 |
| 34 | 2687152135 |
| 35 | 5276362642 |
| 36 | 10078384386 |
| 37 | 21415439670 |
| 38 | 43367751196 |
| 39 | 86613992774 |
| 40 | 166456115593 |
[0,1,1,2,1,5,9,15,30,65,138,274,563,1149,2441, 5110,9090,19645,37524,79178,156697,324182,663749, 1353984,2529510,5088926,10686159,19987129, 40800192,85303150,162549135,341440697,630392773, 1317158898,2687152135,5276362642,10078384386, 21415439670,43367751196,86613992774,166456115593] |