The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 0 |
| 2 | 16 |
| 3 | 16 |
| 4 | 100 |
| 5 | 216 |
| 6 | 844 |
| 7 | 1552 |
| 8 | 7844 |
| 9 | 12112 |
| 10 | 60268 |
| 11 | 118944 |
| 12 | 424072 |
| 13 | 1081392 |
| 14 | 3201728 |
| 15 | 8670688 |
| 16 | 25713154 |
| 17 | 67206560 |
| 18 | 203077760 |
| 19 | 532881432 |
| 20 | 1558159918 |
| 21 | 4250639632 |
| 22 | 11956293152 |
| 23 | 33296697848 |
| 24 | 92820406096 |
| 25 | 257249275776 |
[2,0,16,16,100,216,844,1552,7844,12112,60268, 118944,424072,1081392,3201728,8670688,25713154, 67206560,203077760,532881432,1558159918, 4250639632,11956293152,33296697848,92820406096, 257249275776] |