# A050183 (b-file synthesized from sequence entry) 0 0 1 1 2 4 3 15 4 55 5 200 6 728 7 2652 8 9690 9 35530 10 130750 11 482885 12 1789515 13 6653325 14 24812400 15 92798375 16 347993910 17 1308233790 18 4929576600 19 18615637950 20 70441574000 21 267058714626 22 1014283603024 23 3858687620200 24 14702930414900