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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 4 |
| 6 | 7 |
| 7 | 22 |
| 8 | 31 |
| 9 | 166 |
| 10 | 409 |
| 11 | 2848 |
| 12 | 8224 |
| 13 | 74341 |
| 14 | 301687 |
| 15 | 3626272 |
| 16 | 18878730 |
| 17 | 299451324 |
| 18 | 2103168465 |
| 19 | 44919780098 |
| 20 | 414592933018 |
| 21 | 11582335727655 |
| 22 | 142171297585053 |
| 23 | 5323365939866750 |
| 24 | 86576879487536418 |
| 25 | 4274960797178964894 |
[1,1,1,1,4,7,22,31,166,409,2848,8224,74341,301687, 3626272,18878730,299451324,2103168465,44919780098, 414592933018,11582335727655,142171297585053, 5323365939866750,86576879487536418, 4274960797178964894] |