# A227373 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 6 4 18 5 59 6 199 7 693 8 2465 9 8937 10 32880 11 122513 12 461331 13 1753037 14 6713758 15 25888515 16 100427611 17 391657635 18 1534674930 19 6039078032 20 23855475724 21 94561195899 22 376019415794 23 1499554893338 24 5996061250461 25 24034238674758 26 96554979145357 27 388711331661818 28 1567919554600690