n | a(n) |
---|---|
1 | 0 |
2 | 4 |
3 | 13 |
4 | 45 |
5 | 120 |
6 | 300 |
7 | 692 |
8 | 1524 |
9 | 3225 |
10 | 6625 |
11 | 13280 |
12 | 26096 |
13 | 50432 |
14 | 96100 |
15 | 180925 |
16 | 337085 |
17 | 622328 |
18 | 1139756 |
19 | 2072580 |
20 | 3744980 |
21 | 6728345 |
22 | 12026209 |
23 | 21395328 |
24 | 37901760 |
25 | 66881760 |
26 | 117598660 |
27 | 206094157 |
28 | 360085869 |
29 | 627364920 |
30 | 1090171020 |
[0,4,13,45,120,300,692,1524,3225,6625,13280,26096, 50432,96100,180925,337085,622328,1139756,2072580, 3744980,6728345,12026209,21395328,37901760, 66881760,117598660,206094157,360085869,627364920, 1090171020] |