# A089848 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 2 4 5 5 15 6 42 7 132 8 431 9 1430 10 4862 11 16801 12 58786 13 208012 14 742914 15 2674440 16 9694845 17 35357712 18 129644790 19 477638700 20 1767263322 21 6564120420 22 24466267020 23 91482564069 24 343059613650 25 1289904147324 26 4861946402882 27 18367353072152