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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 8 |
| 2 | 52 |
| 3 | 308 |
| 4 | 2012 |
| 5 | 13308 |
| 6 | 88582 |
| 7 | 590710 |
| 8 | 3941716 |
| 9 | 26308100 |
| 10 | 175600282 |
| 11 | 1172118538 |
| 12 | 7823866514 |
| 13 | 52224288462 |
| 14 | 348597313326 |
| 15 | 2326889050098 |
| 16 | 15531999290132 |
| 17 | 103676198275324 |
| 18 | 692039319384424 |
| 19 | 4619367120609720 |
[1,8,52,308,2012,13308,88582,590710,3941716, 26308100,175600282,1172118538,7823866514, 52224288462,348597313326,2326889050098, 15531999290132,103676198275324,692039319384424, 4619367120609720] |