a(n) = 9*n^2 - 6*n + 2.

Terms

a(0) =5a(1) =26a(2) =65a(3) =122a(4) =197a(5) =290a(6) =401a(7) =530a(8) =677a(9) =842a(10) =1025a(11) =1226a(12) =1445a(13) =1682a(14) =1937a(15) =2210a(16) =2501a(17) =2810a(18) =3137a(19) =3482a(20) =3845a(21) =4226a(22) =4625a(23) =5042a(24) =5477a(25) =5930a(26) =6401a(27) =6890a(28) =7397a(29) =7922