a(n) = n*(n+7)*(n+8)/6.

Terms

a(0) =0a(1) =12a(2) =30a(3) =55a(4) =88a(5) =130a(6) =182a(7) =245a(8) =320a(9) =408a(10) =510a(11) =627a(12) =760a(13) =910a(14) =1078a(15) =1265a(16) =1472a(17) =1700a(18) =1950a(19) =2223a(20) =2520a(21) =2842a(22) =3190a(23) =3565a(24) =3968a(25) =4400a(26) =4862a(27) =5355a(28) =5880a(29) =6438