n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 17 |
3 | 77 |
4 | 374 |
5 | 1959 |
6 | 11085 |
7 | 67500 |
8 | 438485 |
9 | 3004985 |
10 | 21485222 |
11 | 158744467 |
12 | 1202966761 |
13 | 9297312916 |
14 | 72981656937 |
15 | 580105886517 |
16 | 4658713796790 |
17 | 37736326098735 |
18 | 307913254091925 |
19 | 2528335636842300 |
20 | 20875157745756429 |
[1,4,17,77,374,1959,11085,67500,438485,3004985, 21485222,158744467,1202966761,9297312916, 72981656937,580105886517,4658713796790, 37736326098735,307913254091925,2528335636842300, 20875157745756429] |