n | a(n) |
---|---|
0 | 0 |
1 | 2 |
2 | 44 |
3 | 486 |
4 | 3608 |
5 | 20330 |
6 | 93060 |
7 | 361550 |
8 | 1229360 |
9 | 3742290 |
10 | 10377180 |
11 | 26572086 |
12 | 63521352 |
13 | 143027898 |
14 | 305568564 |
15 | 623207070 |
16 | 1219605600 |
17 | 2300164770 |
18 | 4196289420 |
19 | 7428962950 |
20 | 12798246520 |
21 | 21507034122 |
[0,2,44,486,3608,20330,93060,361550,1229360, 3742290,10377180,26572086,63521352,143027898, 305568564,623207070,1219605600,2300164770, 4196289420,7428962950,12798246520,21507034122] |