a(n) = 27225*n^2 - 2*n.

Terms

a(0) =27223a(1) =108896a(2) =245019a(3) =435592a(4) =680615a(5) =980088a(6) =1334011a(7) =1742384a(8) =2205207a(9) =2722480a(10) =3294203a(11) =3920376a(12) =4600999a(13) =5336072a(14) =6125595a(15) =6969568a(16) =7867991a(17) =8820864a(18) =9828187a(19) =10889960a(20) =12006183a(21) =13176856a(22) =14401979a(23) =15681552a(24) =17015575