a(n) = (9*n^2 - 5*n + 2)/2.

Terms

a(0) =1a(1) =3a(2) =14a(3) =34a(4) =63a(5) =101a(6) =148a(7) =204a(8) =269a(9) =343a(10) =426a(11) =518a(12) =619a(13) =729a(14) =848a(15) =976a(16) =1113a(17) =1259a(18) =1414a(19) =1578a(20) =1751a(21) =1933a(22) =2124a(23) =2324a(24) =2533a(25) =2751a(26) =2978a(27) =3214a(28) =3459a(29) =3713