a(n) = (n-1)*(n+4)*(n+6)/6 for n > 1, a(1)=1.

Terms

a(0) =1a(1) =8a(2) =21a(3) =40a(4) =66a(5) =100a(6) =143a(7) =196a(8) =260a(9) =336a(10) =425a(11) =528a(12) =646a(13) =780a(14) =931a(15) =1100a(16) =1288a(17) =1496a(18) =1725a(19) =1976a(20) =2250a(21) =2548a(22) =2871a(23) =3220a(24) =3596a(25) =4000a(26) =4433a(27) =4896a(28) =5390a(29) =5916