n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 16 |
3 | 60 |
4 | 225 |
5 | 840 |
6 | 3136 |
7 | 11704 |
8 | 43681 |
9 | 163020 |
10 | 608400 |
11 | 2270580 |
12 | 8473921 |
13 | 31625104 |
14 | 118026496 |
15 | 440480880 |
16 | 1643897025 |
17 | 6135107220 |
18 | 22896531856 |
19 | 85451020204 |
20 | 318907548961 |
21 | 1190179175640 |
22 | 4441809153600 |
23 | 16577057438760 |
24 | 61866420601441 |
25 | 230888624967004 |
[1,4,16,60,225,840,3136,11704,43681,163020,608400, 2270580,8473921,31625104,118026496,440480880, 1643897025,6135107220,22896531856,85451020204, 318907548961,1190179175640,4441809153600, 16577057438760,61866420601441,230888624967004] |