Number of palindromic compositions of 2*n into parts <= n.

Terms

a(0) =1a(1) =1a(2) =3a(3) =6a(4) =14a(5) =28a(6) =60a(7) =120a(8) =248a(9) =496a(10) =1008a(11) =2016a(12) =4064a(13) =8128a(14) =16320a(15) =32640a(16) =65408a(17) =130816a(18) =261888a(19) =523776a(20) =1048064a(21) =2096128a(22) =4193280a(23) =8386560a(24) =16775168a(25) =33550336a(26) =67104768a(27) =134209536a(28) =268427264a(29) =536854528