# A019437 (b-file synthesized from sequence entry)
0 1
1 3
2 6
3 120
4 9290976268679343135539052852903295259378814351580596958743987989307824385062448596342880785099979140705774497073908459100742234151955724805414557103318958341618000723968000000000000000000000000000