Number of solid standard Young tableaux of shape [[3*n,3],[3]].

Terms

a(0) =0a(1) =192a(2) =7020a(3) =52808a(4) =229680a(5) =738192a(6) =1950512a(7) =4488180a(8) =9314448a(9) =17841200a(10) =32050452a(11) =54630432a(12) =89126240a(13) =140105088a(14) =213336120a(15) =315984812a(16) =456821952a(17) =646447200a(18) =897527228a(19) =1225048440a(20) =1646584272a(21) =2182577072a(22) =2856634560a(23) =3695840868a(24) =4731082160a(25) =5997386832