Even elements to right of central elements in 3-Pascal triangle A028262.

Terms

a(0) =4a(1) =6a(2) =26a(3) =8a(4) =34a(5) =10a(6) =266a(7) =148a(8) =588a(9) =414a(10) =64a(11) =12a(12) =1002a(13) =76a(14) =2178a(15) =880a(16) =14a(17) =430a(18) =6292a(19) =3718a(20) =118a(21) =16a(22) =10010a(23) =2184a(24) =134a(25) =18a(26) =55198a(27) =39832a(28) =22932a(29) =10388