n | a(n) |
---|---|
0 | 0 |
1 | 2 |
2 | 18 |
3 | 90 |
4 | 346 |
5 | 1146 |
6 | 3450 |
7 | 9722 |
8 | 26106 |
9 | 67578 |
10 | 169978 |
11 | 417786 |
12 | 1007610 |
13 | 2392058 |
14 | 5603322 |
15 | 12976122 |
16 | 29753338 |
17 | 67633146 |
18 | 152567802 |
19 | 341835770 |
20 | 761266170 |
21 | 1686110202 |
22 | 3716153338 |
23 | 8153726970 |
24 | 17817403386 |
25 | 38788923386 |
[0,2,18,90,346,1146,3450,9722,26106,67578,169978, 417786,1007610,2392058,5603322,12976122,29753338, 67633146,152567802,341835770,761266170,1686110202, 3716153338,8153726970,17817403386,38788923386] |