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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 3 |
| 7 | 9 |
| 8 | 19 |
| 9 | 41 |
| 10 | 145 |
| 11 | 647 |
| 12 | 3181 |
| 13 | 16339 |
| 14 | 99371 |
| 15 | 747763 |
| 16 | 6609081 |
| 17 | 67311501 |
| 18 | 786968963 |
| 19 | 10964146353 |
| 20 | 178363016765 |
| 21 | 3416486494947 |
| 22 | 75509091003073 |
| 23 | 1969327519976023 |
| 24 | 59733023396132639 |
| 25 | 2140235098426680865 |
[1,1,1,1,1,3,9,19,41,145,647,3181,16339,99371, 747763,6609081,67311501,786968963,10964146353, 178363016765,3416486494947,75509091003073, 1969327519976023,59733023396132639, 2140235098426680865] |