n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 7 |
3 | 27 |
4 | 118 |
5 | 605 |
6 | 3651 |
7 | 25585 |
8 | 204716 |
9 | 1842489 |
10 | 18424945 |
11 | 202674461 |
12 | 2432093610 |
13 | 31617217021 |
14 | 442641038399 |
15 | 6639615576105 |
16 | 106233849217816 |
17 | 1805975436703025 |
18 | 32507557860654621 |
19 | 617643599352437989 |
20 | 12352871987048759990 |
21 | 259410311728023960021 |
[1,2,7,27,118,605,3651,25585,204716,1842489, 18424945,202674461,2432093610,31617217021, 442641038399,6639615576105,106233849217816, 1805975436703025,32507557860654621, 617643599352437989,12352871987048759990, 259410311728023960021] |