The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 3 |
| 2 | 16 |
| 3 | 81 |
| 4 | 392 |
| 5 | 1815 |
| 6 | 8112 |
| 7 | 35301 |
| 8 | 150544 |
| 9 | 632043 |
| 10 | 2620880 |
| 11 | 10759353 |
| 12 | 43804824 |
| 13 | 177105279 |
| 14 | 711809392 |
| 15 | 2846259405 |
| 16 | 11330543648 |
| 17 | 44929049811 |
| 18 | 177540878736 |
| 19 | 699402223137 |
| 20 | 2747583822760 |
| 21 | 10766828545767 |
| 22 | 42095796462896 |
| 23 | 164244726238389 |
| 24 | 639620518118448 |
[0,3,16,81,392,1815,8112,35301,150544,632043, 2620880,10759353,43804824,177105279,711809392, 2846259405,11330543648,44929049811,177540878736, 699402223137,2747583822760,10766828545767, 42095796462896,164244726238389,639620518118448] |