Number of compositions of n with equal number of even and odd parts.

Terms

a(0) =1a(1) =0a(2) =0a(3) =2a(4) =0a(5) =4a(6) =6a(7) =6a(8) =24a(9) =28a(10) =60a(11) =130a(12) =190a(13) =432a(14) =770a(15) =1386a(16) =2856a(17) =5056a(18) =9828a(19) =18918a(20) =34908a(21) =68132a(22) =128502a(23) =244090a(24) =470646a(25) =890628a(26) =1709136a(27) =3271866a(28) =6238986a(29) =11986288