Where records occur in A385485.

Terms

a(0) =1a(1) =2a(2) =12a(3) =126a(4) =252a(5) =504a(6) =2040a(7) =4080a(8) =16380a(9) =32760a(10) =65520a(11) =524286a(12) =1048572a(13) =4194300a(14) =8388600a(15) =134217720a(16) =268435440a(17) =7516192740a(18) =10737418230a(19) =21474836460a(20) =137438953440a(21) =274877906880a(22) =274877906940a(23) =549755813880