Triangle of bifactorial numbers, n B m = (2(n-m)-1)!! (2(n-1))!! / (2(n-m))!!, read by rows.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =4a(5) =8a(6) =15a(7) =18a(8) =24a(9) =48a(10) =105a(11) =120a(12) =144a(13) =192a(14) =384a(15) =945a(16) =1050a(17) =1200a(18) =1440a(19) =1920a(20) =3840a(21) =10395a(22) =11340a(23) =12600a(24) =14400a(25) =17280a(26) =23040a(27) =46080a(28) =135135a(29) =145530