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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 1 |
| 4 | 5 |
| 5 | 5 |
| 6 | 15 |
| 7 | 25 |
| 8 | 68 |
| 9 | 139 |
| 10 | 354 |
| 11 | 813 |
| 12 | 2047 |
| 13 | 4935 |
| 14 | 12421 |
| 15 | 30833 |
| 16 | 78102 |
| 17 | 197139 |
| 18 | 503132 |
| 19 | 1284711 |
| 20 | 3302155 |
| 21 | 8503965 |
| 22 | 21996761 |
| 23 | 57026957 |
| 24 | 148322398 |
| 25 | 386626825 |
| 26 | 1010375144 |
| 27 | 2645762431 |
| 28 | 6942725217 |
| 29 | 18251279163 |
| 30 | 48065184969 |
| 31 | 126783827201 |
[1,2,1,5,5,15,25,68,139,354,813,2047,4935,12421, 30833,78102,197139,503132,1284711,3302155,8503965, 21996761,57026957,148322398,386626825,1010375144, 2645762431,6942725217,18251279163,48065184969, 126783827201] |