# A074187 (b-file synthesized from sequence entry)
1 1
2 1
3 4
4 16
5 100
6 676
7 4913
8 40000
9 362404
10 3625216
11 39904489
12 478996996
13 6226945921
14 87177877081
15 1307672296225
16 20922784184449
17 355687416544329
18 6402373660047556
19 121645099966283776
20 2432902006216007824