Positions of records in A383271.

Terms

a(0) =0a(1) =2a(2) =6a(3) =15a(4) =21a(5) =45a(6) =111a(7) =261a(8) =1605a(9) =1995a(10) =4935a(11) =8295a(12) =69825a(13) =268155a(14) =550725a(15) =4574955a(16) =12024855a(17) =39867135a(18) =398467245a(19) =1698754365a(20) =16351800465