a(n) = n*(n+1)*(n+2)*(n+3)*(n+4)*(2 + 4*n + n^2)/840.

Terms

a(0) =1a(1) =12a(2) =69a(3) =272a(4) =846a(5) =2232a(6) =5214a(7) =11088a(8) =21879a(9) =40612a(10) =71643a(11) =121056a(12) =197132a(13) =310896a(14) =476748a(15) =713184a(16) =1043613a(17) =1497276a(18) =2110273a(19) =2926704a(20) =3999930a(21) =5393960a(22) =7184970a(23) =9462960a(24) =12333555a(25) =15919956a(26) =20365047a(27) =25833664a(28) =32515032a(29) =40625376