a(n) = (1/12)*(n+5)*(n+1)*n^2.

Terms

a(0) =0a(1) =1a(2) =7a(3) =24a(4) =60a(5) =125a(6) =231a(7) =392a(8) =624a(9) =945a(10) =1375a(11) =1936a(12) =2652a(13) =3549a(14) =4655a(15) =6000a(16) =7616a(17) =9537a(18) =11799a(19) =14440a(20) =17500a(21) =21021a(22) =25047a(23) =29624a(24) =34800a(25) =40625a(26) =47151a(27) =54432a(28) =62524a(29) =71485