# A111780 (b-file synthesized from sequence entry)
6 1
7 42
8 1204
9 29736
10 689850
11 15647940
12 354718980
13 8137289160
14 190349674515
15 4561677870750
16 112317990384600
17 2846259737521200
18 74306186469414900
19 1999421553976446600
20 55458660913310655000
21 1585528821898619598000