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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 76 |
| 7 | 232 |
| 8 | 764 |
| 9 | 2620 |
| 10 | 9496 |
| 11 | 35696 |
| 12 | 140151 |
| 13 | 568491 |
| 14 | 2390311 |
| 15 | 10347911 |
| 16 | 46191551 |
| 17 | 211671999 |
| 18 | 996269310 |
| 19 | 4801547628 |
| 20 | 23695885170 |
| 21 | 119481280210 |
| 22 | 615372604033 |
| 23 | 3232009497979 |
| 24 | 17302866542177 |
| 25 | 94301143232321 |
| 26 | 522945331559246 |
| 27 | 2947729723188352 |
[1,1,2,4,10,26,76,232,764,2620,9496,35696,140151, 568491,2390311,10347911,46191551,211671999, 996269310,4801547628,23695885170,119481280210, 615372604033,3232009497979,17302866542177, 94301143232321,522945331559246,2947729723188352] |