Number of compositions of partitions of 2n with exactly n compositions.

Terms

a(0) =1a(1) =2a(2) =8a(3) =24a(4) =80a(5) =224a(6) =704a(7) =1920a(8) =5632a(9) =15360a(10) =43008a(11) =114688a(12) =315392a(13) =827392a(14) =2211840a(15) =5767168a(16) =15138816a(17) =38928384a(18) =100925440a(19) =256901120a(20) =657457152a(21) =1660944384a(22) =4202692608a(23) =10527703040a(24) =26424115200a(25) =65699577856a(26) =163477192704a(27) =403995361280a(28) =998043025408