# A118677 (b-file synthesized from sequence entry) 0 1 1 2 2 6 3 18 4 60 5 202 6 718 7 2600 8 9748 9 37270 10 146058 11 582548 12 2367028 13 9761890 14 40844168 15 173001018 16 741193056 17 3207480526 18 14008373662 19 61683982696 20 273658651700 21 1222314257450 22 5493414465900 23 24828463984518