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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 27 |
| 3 | 251 |
| 4 | 908 |
| 5 | 7387 |
| 6 | 9449 |
| 7 | 42221 |
| 8 | 39528 |
| 9 | 138840 |
| 10 | 454766 |
| 11 | 250398 |
| 12 | 1201227 |
| 13 | 1315046 |
| 14 | 860814 |
| 15 | 2227899 |
| 16 | 4949209 |
| 17 | 7528262 |
| 18 | 3228855 |
| 19 | 12360603 |
| 20 | 10884568 |
| 21 | 6372164 |
| 22 | 23452759 |
| 23 | 19814016 |
| 24 | 37234487 |
| 25 | 66650343 |
| 26 | 42039006 |
| 27 | 23501193 |
| 28 | 52437822 |
| 29 | 29137840 |
| 30 | 64622169 |
| 31 | 304995118 |
[4,27,251,908,7387,9449,42221,39528,138840,454766, 250398,1201227,1315046,860814,2227899,4949209, 7528262,3228855,12360603,10884568,6372164, 23452759,19814016,37234487,66650343,42039006, 23501193,52437822,29137840,64622169,304995118] |