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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 41 |
| 4 | 180 |
| 5 | 745 |
| 6 | 3016 |
| 7 | 12113 |
| 8 | 48516 |
| 9 | 194145 |
| 10 | 776680 |
| 11 | 3106841 |
| 12 | 12427508 |
| 13 | 49710201 |
| 14 | 198841000 |
| 15 | 795364225 |
| 16 | 3181457156 |
| 17 | 12725828913 |
| 18 | 50903315976 |
| 19 | 203613264265 |
| 20 | 814453057460 |
| 21 | 3257812230281 |
| 22 | 13031248921608 |
| 23 | 52124995686961 |
| 24 | 208499982748420 |
| 25 | 833999930994305 |
[0,1,8,41,180,745,3016,12113,48516,194145,776680, 3106841,12427508,49710201,198841000,795364225, 3181457156,12725828913,50903315976,203613264265, 814453057460,3257812230281,13031248921608, 52124995686961,208499982748420,833999930994305] |