login

A057500 as a simple table

na(n)
10
20
31
415
5222
63660
768295
81436568
933779340
10880107840
1125201854045
12787368574080
1326667815195274
14973672928417280
1538132879409281475
161594927540549217280
1770964911709203684440
183347306760024413356032
19166855112441313024389625
208765006377126199463936000

[0,0,1,15,222,3660,68295,1436568,33779340,
 880107840,25201854045,787368574080,26667815195274,
 973672928417280,38132879409281475,
 1594927540549217280,70964911709203684440,
 3347306760024413356032,166855112441313024389625,
 8765006377126199463936000]