# A117735 (b-file synthesized from sequence entry)
0 0
1 0
2 0
3 0
4 18
5 90
6 690
7 4830
8 40110
9 362670
10 3628590
11 39914490
12 478999290
13 6226990770
14 87178261170
15 1307674337970
16 20922789857970
17 355687427585490
18 6402373705217490
19 121645100399132310
20 2432902008166940310