a(n) = binomial(n+3,3)*binomial(n+8,3).

Terms

a(0) =56a(1) =336a(2) =1200a(3) =3300a(4) =7700a(5) =16016a(6) =30576a(7) =54600a(8) =92400a(9) =149600a(10) =233376a(11) =352716a(12) =518700a(13) =744800a(14) =1047200a(15) =1445136a(16) =1961256a(17) =2622000a(18) =3458000a(19) =4504500a(20) =5801796a(21) =7395696a(22) =9338000a(23) =11687000a(24) =14508000a(25) =17873856a(26) =21865536a(27) =26572700a(28) =32094300a(29) =38539200