A090801(2n-1)+A090801(2n).

Terms

a(0) =3a(1) =36a(2) =108a(3) =420a(4) =684a(5) =1008a(6) =1332a(7) =1668a(8) =2076a(9) =2772a(10) =2952a(11) =3168a(12) =3576a(13) =4236a(14) =4776a(15) =5148a(16) =5532a(17) =5892a(18) =6312a(19) =6696a(20) =7008a(21) =7776a(22) =8064a(23) =8640a(24) =8964a(25) =9648a(26) =10044a(27) =10368a(28) =10692a(29) =11376