# A010580 (b-file synthesized from sequence entry)
0 1
1 12
2 132
3 1452
4 15852
5 173052
6 1884972
7 20532252
8 223437852
9 2431526492
10 26447593812
11 287669976492
12 3128064123732
13 34013987172972
14 369792173040492
15 4020299656610636
16 43702216875039660
17 475060467524653980
18 5163624600479230260
19 56125562454502452780
20 610010748386503122684