# A103931 (b-file synthesized from sequence entry)
1 1
2 4
3 36
4 144
5 3600
6 400
7 19600
8 78400
9 6350400
10 6350400
11 768398400
12 768398400
13 129859329600
14 129859329600
15 129859329600
16 519437318400
17 150117385017600
18 16679709446400
19 6021375110150400
20 240855004406016
21 26761667156224