a(n) = f(n,4) where f is given in A034261.

Terms

a(0) =0a(1) =1a(2) =11a(3) =56a(4) =196a(5) =546a(6) =1302a(7) =2772a(8) =5412a(9) =9867a(10) =17017a(11) =28028a(12) =44408a(13) =68068a(14) =101388a(15) =147288a(16) =209304a(17) =291669a(18) =399399a(19) =538384a(20) =715484a(21) =938630a(22) =1216930a(23) =1560780a(24) =1981980a(25) =2493855a(26) =3111381a(27) =3851316a(28) =4732336a(29) =5775176