a(n) = 729*n^2 - 442*n + 67.

Terms

a(0) =354a(1) =2099a(2) =5302a(3) =9963a(4) =16082a(5) =23659a(6) =32694a(7) =43187a(8) =55138a(9) =68547a(10) =83414a(11) =99739a(12) =117522a(13) =136763a(14) =157462a(15) =179619a(16) =203234a(17) =228307a(18) =254838a(19) =282827a(20) =312274a(21) =343179a(22) =375542a(23) =409363a(24) =444642a(25) =481379a(26) =519574a(27) =559227a(28) =600338a(29) =642907