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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 8 |
| 3 | 23 |
| 4 | 64 |
| 5 | 175 |
| 6 | 472 |
| 7 | 1259 |
| 8 | 3328 |
| 9 | 8731 |
| 10 | 22760 |
| 11 | 59007 |
| 12 | 152256 |
| 13 | 391239 |
| 14 | 1001656 |
| 15 | 2556115 |
| 16 | 6503936 |
| 17 | 16505651 |
| 18 | 41788616 |
| 19 | 105571303 |
| 20 | 266181440 |
| 21 | 669923039 |
| 22 | 1683255448 |
| 23 | 4222878651 |
| 24 | 10579130112 |
| 25 | 26467818315 |
| 26 | 66138242984 |
| 27 | 165077936207 |
| 28 | 411584855488 |
| 29 | 1025162759287 |
[1,3,8,23,64,175,472,1259,3328,8731,22760,59007, 152256,391239,1001656,2556115,6503936,16505651, 41788616,105571303,266181440,669923039,1683255448, 4222878651,10579130112,26467818315,66138242984, 165077936207,411584855488,1025162759287] |