Smallest k such that k*n is a double factorial.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =8a(6) =15a(7) =1a(8) =105a(9) =384a(10) =945a(11) =4a(12) =10395a(13) =46080a(14) =1a(15) =3a(16) =2027025a(17) =2560a(18) =34459425a(19) =192a(20) =5a(21) =3715891200a(22) =13749310575a(23) =2a(24) =81081a(26) =35a(27) =23040a(29) =128a(31) =12