| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 18 |
| 4 | 72 |
| 5 | 200 |
| 6 | 378 |
| 7 | 588 |
| 8 | 1312 |
| 9 | 2106 |
| 10 | 3650 |
| 11 | 4840 |
| 12 | 7848 |
| 13 | 10140 |
| 14 | 14210 |
| 15 | 20250 |
| 16 | 25728 |
| 17 | 32368 |
| 18 | 42282 |
| 19 | 51984 |
| 20 | 67400 |
| 21 | 80262 |
| 22 | 97042 |
| 23 | 116380 |
| 24 | 141984 |
| 25 | 167500 |
| 26 | 195026 |
| 27 | 228906 |
| 28 | 266952 |
| 29 | 306124 |
| 30 | 358650 |
| 31 | 403620 |
| 32 | 463360 |
| 33 | 524898 |
| 34 | 592450 |
| 35 | 671300 |
| 36 | 754920 |
| 37 | 837828 |
| 38 | 936434 |
[0,2,18,72,200,378,588,1312,2106,3650,4840,7848, 10140,14210,20250,25728,32368,42282,51984,67400, 80262,97042,116380,141984,167500,195026,228906, 266952,306124,358650,403620,463360,524898,592450, 671300,754920,837828,936434] |