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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 12 |
| 6 | 32 |
| 7 | 109 |
| 8 | 366 |
| 9 | 1189 |
| 10 | 9855 |
| 11 | 58994 |
| 12 | 296022 |
| 13 | 1959725 |
| 14 | 11368311 |
| 15 | 60437981 |
| 16 | 345527448 |
| 17 | 1904249259 |
| 18 | 10390269667 |
| 19 | 64901329419 |
| 20 | 387065403450 |
| 21 | 2241102587830 |
| 22 | 13656975359566 |
| 23 | 81191938320012 |
| 24 | 473207108106993 |
| 25 | 2804086644305202 |
[1,1,1,4,12,32,109,366,1189,9855,58994,296022, 1959725,11368311,60437981,345527448,1904249259, 10390269667,64901329419,387065403450, 2241102587830,13656975359566,81191938320012, 473207108106993,2804086644305202] |