| n | a(n) |
|---|---|
| 3 | 2 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 26 |
| 10 | 86 |
| 11 | 228 |
| 12 | 424 |
| 13 | 1040 |
| 14 | 2192 |
| 15 | 5632 |
| 16 | 13820 |
| 17 | 37462 |
| 18 | 94070 |
| 19 | 244632 |
| 20 | 612400 |
| 21 | 1576680 |
| 22 | 3994116 |
| 23 | 10322016 |
| 24 | 26512176 |
| 25 | 69006942 |
| 26 | 178963650 |
| 27 | 467609932 |
| 28 | 1219902008 |
| 29 | 3198150306 |
| 30 | 8381973582 |
| 31 | 22048632000 |
[2,0,0,0,0,0,26,86,228,424,1040,2192,5632,13820, 37462,94070,244632,612400,1576680,3994116, 10322016,26512176,69006942,178963650,467609932, 1219902008,3198150306,8381973582,22048632000] |