| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 18 |
| 2 | 162 |
| 3 | 927 |
| 4 | 3906 |
| 5 | 13248 |
| 6 | 38256 |
| 7 | 97614 |
| 8 | 225819 |
| 9 | 482482 |
| 10 | 965250 |
| 11 | 1827189 |
| 12 | 3299556 |
| 13 | 5720976 |
| 14 | 9574128 |
| 15 | 15531132 |
| 16 | 24508917 |
| 17 | 37735938 |
| 18 | 56831698 |
| 19 | 83900619 |
| 20 | 121641894 |
| 21 | 173477040 |
| 22 | 243696960 |
| 23 | 337630410 |
| 24 | 461835855 |
| 25 | 624318786 |
| 26 | 834776658 |
| 27 | 1104873697 |
| 28 | 1448547912 |
| 29 | 1882352736 |
| 30 | 2425835808 |
[1,18,162,927,3906,13248,38256,97614,225819, 482482,965250,1827189,3299556,5720976,9574128, 15531132,24508917,37735938,56831698,83900619, 121641894,173477040,243696960,337630410,461835855, 624318786,834776658,1104873697,1448547912, 1882352736,2425835808] |