# A002553 (b-file synthesized from sequence entry)
0 1
1 24
2 640
3 7168
4 294912
5 2883584
6 54525952
7 167772160
8 36507222016
9 326417514496
10 5772436045824
11 50577534877696
12 1759218604441600
13 15199648742375424
14 261208778387488768
15 2233785415175766016
16 101457092405402533888