overview of finiteness proof Gerog comment "not helpful", adding more intuitions of "closed forms"
1 16
2 43
3 97
4 205
5 421
6 853
7 1717
8 3445
9 6901
10 13813
11 27637
12 55285
13 110581
14 221173
15 442357
16 884725
17 1769461
18 3538933
19 7077877