a(n) = A014486(A122228(n)).

Terms

a(0) =0a(1) =2a(2) =12a(3) =56a(4) =228a(5) =920a(6) =3684a(7) =14744a(8) =58980a(9) =235928a(10) =943716a(11) =3774872a(12) =15099492a(13) =60397976a(14) =241591908a(15) =966367640a(16) =3865470564a(17) =15461882264a(18) =61847529060a(19) =247390116248a(20) =989560464996