Even elements to right of central elements in 4-Pascal triangle A028275.

Terms

a(0) =6a(1) =16a(2) =8a(3) =86a(4) =40a(5) =10a(6) =196a(7) =126a(8) =50a(9) =322a(10) =176a(11) =12a(12) =714a(13) =498a(14) =1212a(15) =310a(16) =86a(17) =14a(18) =2640a(19) =396a(20) =100a(21) =2992a(22) =496a(23) =16a(24) =17446a(25) =12012a(26) =6370a(27) =2548a(28) =742a(29) =148