# A035800 (b-file synthesized from sequence entry) 0 1 1 60 2 1800 3 36020 4 541200 5 6516012 6 65520920 7 566262180 8 4296107040 9 29081139740 10 177923724072 11 994286700180 12 5119703270960 13 24470719227660 14 109262828065080 15 458260342666116 16 1814109445277760 17 6807471232021500